Snyk Code Report
- JavaScript files: 16
- Python files: 678
- XML files: 5
- C files: 1
- HTML files: 73
Selection of Less-Secure Algorithm During Negotiation (SSL instead of TLS)
Consider using TLS instead of SSL (ssl.PROTOCOL_SSLv23 used in ssl.wrap_socket).
⇣ Data Flow
ssl.PROTOCOL_SSLv23,
ssl.wrap_socket(sock, self.key_file, self.cert_file,
✓ Fix Analysis
Details
Implementing encryption for the transmission and storage of sensitive information is essential. But encryption standards are constantly changing since attackers have more and more powerful resources at their disposal-along with more sophisticated attack algorithms. This means that encryption is only useful if it meets current standards appropriate for the type of data being transmitted or stored. When organizations use weakly encoded passwords or weak hashes (especially when they also utilize single-factor authentication, which places too much emphasis on passwords), attackers can potentially gain unauthorized access through a brute-force attack.
Best practices for prevention
- Use TLS instead of SSL
Selection of Less-Secure Algorithm During Negotiation (SSL instead of TLS)
Consider using TLS instead of SSL (ssl.PROTOCOL_SSLv23 used in ssl.SSLContext).
⇣ Data Flow
ssl.PROTOCOL_SSLv23)
ssl.SSLContext(ssl.PROTOCOL_SSLv23)
✓ Fix Analysis
Details
Implementing encryption for the transmission and storage of sensitive information is essential. But encryption standards are constantly changing since attackers have more and more powerful resources at their disposal-along with more sophisticated attack algorithms. This means that encryption is only useful if it meets current standards appropriate for the type of data being transmitted or stored. When organizations use weakly encoded passwords or weak hashes (especially when they also utilize single-factor authentication, which places too much emphasis on passwords), attackers can potentially gain unauthorized access through a brute-force attack.
Best practices for prevention
- Use TLS instead of SSL
SQL Injection
Unsanitized input from a web form flows into execute, where it is used in an SQL query. This may result in an SQL Injection vulnerability.
⇣ Data Flow
request.form['divisa_origen']
request.form['divisa_origen']
request.form['divisa_origen']
divisa_origen = request.form['divisa_origen']
divisa_origen, divisa_destino)
divisa_origen, divisa_destino, monto, monto_convertido):
divisa_destino, monto, monto_convertido):
divisa_destino}, Monto: {monto}, Monto convertido: {monto_convertido}")
divisa_destino}...")
divisa_destino} FROM Accounts WHERE UserId = ?", (user_id,))
divisa_destino}: {balance_destino}")
divisa_destino}: {nuevo_balance_destino}")
divisa_destino} = ? WHERE UserId = ?",
f"UPDATE Accounts SET Balance{divisa_destino} = ? WHERE UserId = ?",
cursor.execute(f"UPDATE Accounts SET Balance{divisa_destino} = ? WHERE UserId = ?",
✓ Fix Analysis
Details
In an SQL injection attack, the user can submit an SQL query directly to the database, gaining access without providing appropriate credentials. Attackers can then view, export, modify, and delete confidential information; change passwords and other authentication information; and possibly gain access to other systems within the network. This is one of the most commonly exploited categories of vulnerability, but can largely be avoided through good coding practices.
Best practices for prevention
- Avoid passing user-entered parameters directly to the SQL server.
- Avoid using string concatenation to build SQL queries from user-entered parameters.
- When coding, define SQL code first, then pass in parameters. Use prepared statements with parameterized queries. Examples include
SqlCommand()in .NET andbindParam()in PHP. - Use strong typing for all parameters so unexpected user data will be rejected.
- Where direct user input cannot be avoided for performance reasons, validate input against a very strict allowlist of permitted characters, avoiding special characters such as
? & / < > ; - ' " \and spaces. Use a vendor-supplied escaping routine if possible. - Develop your application in an environment and/or using libraries that provide protection against SQL injection.
- Harden your entire environment around a least-privilege model, ideally with isolated accounts with privileges only for particular tasks.
Cross-site Scripting (XSS)
Unsanitized input from the document location flows into a 'src' script element attribute, where it is used to dynamically construct the HTML page on client side. This may result in a DOM Based Cross-Site Scripting attack (DOMXSS).
⇣ Data Flow
href;
href;
url = window.location.href;
url.indexOf('?');
url.substr(startOfQueryString) : '';
substr(startOfQueryString) : '';
queryString = startOfQueryString > -1 ? url.substr(startOfQueryString) : '';
queryString;
'class.js' + queryString;
✓ Fix Analysis
Details
A cross-site scripting attack occurs when the attacker tricks a legitimate web-based application or site to accept a request as originating from a trusted source.
This is done by escaping the context of the web application; the web application then delivers that data to its users along with other trusted dynamic content, without validating it. The browser unknowingly executes malicious script on the client side (through client-side languages; usually JavaScript or HTML) in order to perform actions that are otherwise typically blocked by the browser's Same Origin Policy.
Injecting malicious code is the most prevalent manner by which XSS is exploited; for this reason, escaping characters in order to prevent this manipulation is the top method for securing code against this vulnerability.
Escaping means that the application is coded to mark key characters, and particularly key characters included in user input, to prevent those characters from being interpreted in a dangerous context. For example, in HTML, < can be coded as < and > can be coded as > in order to be interpreted and displayed as themselves in text, while within the code itself, they are used for HTML tags. If malicious content is injected into an application that escapes special characters and that malicious content uses < and > as HTML tags, those characters are nonetheless not interpreted as HTML tags by the browser if they've been correctly escaped in the application code and in this way the attempted attack is diverted.
The most prominent use of XSS is to steal cookies (source: OWASP HttpOnly) and hijack user sessions, but XSS exploits have been used to expose sensitive information, enable access to privileged services and functionality and deliver malware.
Types of attacks
There are a few methods by which XSS can be manipulated:
| Type | Origin | Description |
|---|---|---|
| Stored | Server | The malicious code is inserted in the application (usually as a link) by the attacker. The code is activated every time a user clicks the link. |
| Reflected | Server | The attacker delivers a malicious link externally from the vulnerable web site application to a user. When clicked, malicious code is sent to the vulnerable web site, which reflects the attack back to the user's browser. |
| DOM-based | Client | The attacker forces the user's browser to render a malicious page. The data in the page itself delivers the cross-site scripting data. |
| Mutated | The attacker injects code that appears safe, but is then rewritten and modified by the browser, while parsing the markup. An example is rebalancing unclosed quotation marks or even adding quotation marks to unquoted parameters. |
Affected environments
The following environments are susceptible to an XSS attack:
- Web servers
- Application servers
- Web application environments
Best practices for prevention
This section describes the top best practices designed to specifically protect your code:
- Sanitize data input in an HTTP request before reflecting it back, ensuring all data is validated, filtered or escaped before echoing anything back to the user, such as the values of query parameters during searches.
- Convert special characters such as
?,&,/,<,>and spaces to their respective HTML or URL encoded equivalents. - Give users the option to disable client-side scripts.
- Redirect invalid requests.
- Detect simultaneous logins, including those from two separate IP addresses, and invalidate those sessions.
- Use and enforce a Content Security Policy (source: Wikipedia) to disable any features that might be manipulated for an XSS attack.
- Read the documentation for any of the libraries referenced in your code to understand which elements allow for embedded HTML.
Cross-site Scripting (XSS)
Unsanitized input from the document location flows into a 'src' script element attribute, where it is used to dynamically construct the HTML page on client side. This may result in a DOM Based Cross-Site Scripting attack (DOMXSS).
⇣ Data Flow
href;
href;
url = window.location.href;
url.indexOf('?');
url.substr(startOfQueryString) : '';
substr(startOfQueryString) : '';
queryString = startOfQueryString > -1 ? url.substr(startOfQueryString) : '';
queryString;
'main.js' + queryString;
✓ Fix Analysis
Details
A cross-site scripting attack occurs when the attacker tricks a legitimate web-based application or site to accept a request as originating from a trusted source.
This is done by escaping the context of the web application; the web application then delivers that data to its users along with other trusted dynamic content, without validating it. The browser unknowingly executes malicious script on the client side (through client-side languages; usually JavaScript or HTML) in order to perform actions that are otherwise typically blocked by the browser's Same Origin Policy.
Injecting malicious code is the most prevalent manner by which XSS is exploited; for this reason, escaping characters in order to prevent this manipulation is the top method for securing code against this vulnerability.
Escaping means that the application is coded to mark key characters, and particularly key characters included in user input, to prevent those characters from being interpreted in a dangerous context. For example, in HTML, < can be coded as < and > can be coded as > in order to be interpreted and displayed as themselves in text, while within the code itself, they are used for HTML tags. If malicious content is injected into an application that escapes special characters and that malicious content uses < and > as HTML tags, those characters are nonetheless not interpreted as HTML tags by the browser if they've been correctly escaped in the application code and in this way the attempted attack is diverted.
The most prominent use of XSS is to steal cookies (source: OWASP HttpOnly) and hijack user sessions, but XSS exploits have been used to expose sensitive information, enable access to privileged services and functionality and deliver malware.
Types of attacks
There are a few methods by which XSS can be manipulated:
| Type | Origin | Description |
|---|---|---|
| Stored | Server | The malicious code is inserted in the application (usually as a link) by the attacker. The code is activated every time a user clicks the link. |
| Reflected | Server | The attacker delivers a malicious link externally from the vulnerable web site application to a user. When clicked, malicious code is sent to the vulnerable web site, which reflects the attack back to the user's browser. |
| DOM-based | Client | The attacker forces the user's browser to render a malicious page. The data in the page itself delivers the cross-site scripting data. |
| Mutated | The attacker injects code that appears safe, but is then rewritten and modified by the browser, while parsing the markup. An example is rebalancing unclosed quotation marks or even adding quotation marks to unquoted parameters. |
Affected environments
The following environments are susceptible to an XSS attack:
- Web servers
- Application servers
- Web application environments
Best practices for prevention
This section describes the top best practices designed to specifically protect your code:
- Sanitize data input in an HTTP request before reflecting it back, ensuring all data is validated, filtered or escaped before echoing anything back to the user, such as the values of query parameters during searches.
- Convert special characters such as
?,&,/,<,>and spaces to their respective HTML or URL encoded equivalents. - Give users the option to disable client-side scripts.
- Redirect invalid requests.
- Detect simultaneous logins, including those from two separate IP addresses, and invalidate those sessions.
- Use and enforce a Content Security Policy (source: Wikipedia) to disable any features that might be manipulated for an XSS attack.
- Read the documentation for any of the libraries referenced in your code to understand which elements allow for embedded HTML.
Cross-site Scripting (XSS)
Unsanitized input from the document location flows into a 'src' script element attribute, where it is used to dynamically construct the HTML page on client side. This may result in a DOM Based Cross-Site Scripting attack (DOMXSS).
⇣ Data Flow
href;
href;
url = window.location.href;
url.indexOf('?');
url.substr(startOfQueryString) : '';
substr(startOfQueryString) : '';
queryString = startOfQueryString > -1 ? url.substr(startOfQueryString) : '';
queryString;
'class.js' + queryString;
✓ Fix Analysis
Details
A cross-site scripting attack occurs when the attacker tricks a legitimate web-based application or site to accept a request as originating from a trusted source.
This is done by escaping the context of the web application; the web application then delivers that data to its users along with other trusted dynamic content, without validating it. The browser unknowingly executes malicious script on the client side (through client-side languages; usually JavaScript or HTML) in order to perform actions that are otherwise typically blocked by the browser's Same Origin Policy.
Injecting malicious code is the most prevalent manner by which XSS is exploited; for this reason, escaping characters in order to prevent this manipulation is the top method for securing code against this vulnerability.
Escaping means that the application is coded to mark key characters, and particularly key characters included in user input, to prevent those characters from being interpreted in a dangerous context. For example, in HTML, < can be coded as < and > can be coded as > in order to be interpreted and displayed as themselves in text, while within the code itself, they are used for HTML tags. If malicious content is injected into an application that escapes special characters and that malicious content uses < and > as HTML tags, those characters are nonetheless not interpreted as HTML tags by the browser if they've been correctly escaped in the application code and in this way the attempted attack is diverted.
The most prominent use of XSS is to steal cookies (source: OWASP HttpOnly) and hijack user sessions, but XSS exploits have been used to expose sensitive information, enable access to privileged services and functionality and deliver malware.
Types of attacks
There are a few methods by which XSS can be manipulated:
| Type | Origin | Description |
|---|---|---|
| Stored | Server | The malicious code is inserted in the application (usually as a link) by the attacker. The code is activated every time a user clicks the link. |
| Reflected | Server | The attacker delivers a malicious link externally from the vulnerable web site application to a user. When clicked, malicious code is sent to the vulnerable web site, which reflects the attack back to the user's browser. |
| DOM-based | Client | The attacker forces the user's browser to render a malicious page. The data in the page itself delivers the cross-site scripting data. |
| Mutated | The attacker injects code that appears safe, but is then rewritten and modified by the browser, while parsing the markup. An example is rebalancing unclosed quotation marks or even adding quotation marks to unquoted parameters. |
Affected environments
The following environments are susceptible to an XSS attack:
- Web servers
- Application servers
- Web application environments
Best practices for prevention
This section describes the top best practices designed to specifically protect your code:
- Sanitize data input in an HTTP request before reflecting it back, ensuring all data is validated, filtered or escaped before echoing anything back to the user, such as the values of query parameters during searches.
- Convert special characters such as
?,&,/,<,>and spaces to their respective HTML or URL encoded equivalents. - Give users the option to disable client-side scripts.
- Redirect invalid requests.
- Detect simultaneous logins, including those from two separate IP addresses, and invalidate those sessions.
- Use and enforce a Content Security Policy (source: Wikipedia) to disable any features that might be manipulated for an XSS attack.
- Read the documentation for any of the libraries referenced in your code to understand which elements allow for embedded HTML.
Cross-site Scripting (XSS)
Unsanitized input from the document location flows into a 'src' script element attribute, where it is used to dynamically construct the HTML page on client side. This may result in a DOM Based Cross-Site Scripting attack (DOMXSS).
⇣ Data Flow
href;
href;
url = window.location.href;
url.indexOf('?');
url.substr(startOfQueryString) : '';
substr(startOfQueryString) : '';
queryString = startOfQueryString > -1 ? url.substr(startOfQueryString) : '';
queryString;
'class.js' + queryString;
✓ Fix Analysis
Details
A cross-site scripting attack occurs when the attacker tricks a legitimate web-based application or site to accept a request as originating from a trusted source.
This is done by escaping the context of the web application; the web application then delivers that data to its users along with other trusted dynamic content, without validating it. The browser unknowingly executes malicious script on the client side (through client-side languages; usually JavaScript or HTML) in order to perform actions that are otherwise typically blocked by the browser's Same Origin Policy.
Injecting malicious code is the most prevalent manner by which XSS is exploited; for this reason, escaping characters in order to prevent this manipulation is the top method for securing code against this vulnerability.
Escaping means that the application is coded to mark key characters, and particularly key characters included in user input, to prevent those characters from being interpreted in a dangerous context. For example, in HTML, < can be coded as < and > can be coded as > in order to be interpreted and displayed as themselves in text, while within the code itself, they are used for HTML tags. If malicious content is injected into an application that escapes special characters and that malicious content uses < and > as HTML tags, those characters are nonetheless not interpreted as HTML tags by the browser if they've been correctly escaped in the application code and in this way the attempted attack is diverted.
The most prominent use of XSS is to steal cookies (source: OWASP HttpOnly) and hijack user sessions, but XSS exploits have been used to expose sensitive information, enable access to privileged services and functionality and deliver malware.
Types of attacks
There are a few methods by which XSS can be manipulated:
| Type | Origin | Description |
|---|---|---|
| Stored | Server | The malicious code is inserted in the application (usually as a link) by the attacker. The code is activated every time a user clicks the link. |
| Reflected | Server | The attacker delivers a malicious link externally from the vulnerable web site application to a user. When clicked, malicious code is sent to the vulnerable web site, which reflects the attack back to the user's browser. |
| DOM-based | Client | The attacker forces the user's browser to render a malicious page. The data in the page itself delivers the cross-site scripting data. |
| Mutated | The attacker injects code that appears safe, but is then rewritten and modified by the browser, while parsing the markup. An example is rebalancing unclosed quotation marks or even adding quotation marks to unquoted parameters. |
Affected environments
The following environments are susceptible to an XSS attack:
- Web servers
- Application servers
- Web application environments
Best practices for prevention
This section describes the top best practices designed to specifically protect your code:
- Sanitize data input in an HTTP request before reflecting it back, ensuring all data is validated, filtered or escaped before echoing anything back to the user, such as the values of query parameters during searches.
- Convert special characters such as
?,&,/,<,>and spaces to their respective HTML or URL encoded equivalents. - Give users the option to disable client-side scripts.
- Redirect invalid requests.
- Detect simultaneous logins, including those from two separate IP addresses, and invalidate those sessions.
- Use and enforce a Content Security Policy (source: Wikipedia) to disable any features that might be manipulated for an XSS attack.
- Read the documentation for any of the libraries referenced in your code to understand which elements allow for embedded HTML.
Cross-site Scripting (XSS)
Unsanitized input from the document location flows into a 'src' script element attribute, where it is used to dynamically construct the HTML page on client side. This may result in a DOM Based Cross-Site Scripting attack (DOMXSS).
⇣ Data Flow
href;
href;
url = window.location.href;
url.indexOf('?');
url.substr(startOfQueryString) : '';
substr(startOfQueryString) : '';
queryString = startOfQueryString > -1 ? url.substr(startOfQueryString) : '';
queryString;
'main.js' + queryString;
✓ Fix Analysis
Details
A cross-site scripting attack occurs when the attacker tricks a legitimate web-based application or site to accept a request as originating from a trusted source.
This is done by escaping the context of the web application; the web application then delivers that data to its users along with other trusted dynamic content, without validating it. The browser unknowingly executes malicious script on the client side (through client-side languages; usually JavaScript or HTML) in order to perform actions that are otherwise typically blocked by the browser's Same Origin Policy.
Injecting malicious code is the most prevalent manner by which XSS is exploited; for this reason, escaping characters in order to prevent this manipulation is the top method for securing code against this vulnerability.
Escaping means that the application is coded to mark key characters, and particularly key characters included in user input, to prevent those characters from being interpreted in a dangerous context. For example, in HTML, < can be coded as < and > can be coded as > in order to be interpreted and displayed as themselves in text, while within the code itself, they are used for HTML tags. If malicious content is injected into an application that escapes special characters and that malicious content uses < and > as HTML tags, those characters are nonetheless not interpreted as HTML tags by the browser if they've been correctly escaped in the application code and in this way the attempted attack is diverted.
The most prominent use of XSS is to steal cookies (source: OWASP HttpOnly) and hijack user sessions, but XSS exploits have been used to expose sensitive information, enable access to privileged services and functionality and deliver malware.
Types of attacks
There are a few methods by which XSS can be manipulated:
| Type | Origin | Description |
|---|---|---|
| Stored | Server | The malicious code is inserted in the application (usually as a link) by the attacker. The code is activated every time a user clicks the link. |
| Reflected | Server | The attacker delivers a malicious link externally from the vulnerable web site application to a user. When clicked, malicious code is sent to the vulnerable web site, which reflects the attack back to the user's browser. |
| DOM-based | Client | The attacker forces the user's browser to render a malicious page. The data in the page itself delivers the cross-site scripting data. |
| Mutated | The attacker injects code that appears safe, but is then rewritten and modified by the browser, while parsing the markup. An example is rebalancing unclosed quotation marks or even adding quotation marks to unquoted parameters. |
Affected environments
The following environments are susceptible to an XSS attack:
- Web servers
- Application servers
- Web application environments
Best practices for prevention
This section describes the top best practices designed to specifically protect your code:
- Sanitize data input in an HTTP request before reflecting it back, ensuring all data is validated, filtered or escaped before echoing anything back to the user, such as the values of query parameters during searches.
- Convert special characters such as
?,&,/,<,>and spaces to their respective HTML or URL encoded equivalents. - Give users the option to disable client-side scripts.
- Redirect invalid requests.
- Detect simultaneous logins, including those from two separate IP addresses, and invalidate those sessions.
- Use and enforce a Content Security Policy (source: Wikipedia) to disable any features that might be manipulated for an XSS attack.
- Read the documentation for any of the libraries referenced in your code to understand which elements allow for embedded HTML.
Cross-site Scripting (XSS)
Unsanitized input from the document location flows into a 'src' script element attribute, where it is used to dynamically construct the HTML page on client side. This may result in a DOM Based Cross-Site Scripting attack (DOMXSS).
⇣ Data Flow
href;
href;
url = window.location.href;
url.indexOf('?');
url.substr(startOfQueryString) : '';
substr(startOfQueryString) : '';
queryString = startOfQueryString > -1 ? url.substr(startOfQueryString) : '';
queryString;
'class.js' + queryString;
✓ Fix Analysis
Details
A cross-site scripting attack occurs when the attacker tricks a legitimate web-based application or site to accept a request as originating from a trusted source.
This is done by escaping the context of the web application; the web application then delivers that data to its users along with other trusted dynamic content, without validating it. The browser unknowingly executes malicious script on the client side (through client-side languages; usually JavaScript or HTML) in order to perform actions that are otherwise typically blocked by the browser's Same Origin Policy.
Injecting malicious code is the most prevalent manner by which XSS is exploited; for this reason, escaping characters in order to prevent this manipulation is the top method for securing code against this vulnerability.
Escaping means that the application is coded to mark key characters, and particularly key characters included in user input, to prevent those characters from being interpreted in a dangerous context. For example, in HTML, < can be coded as < and > can be coded as > in order to be interpreted and displayed as themselves in text, while within the code itself, they are used for HTML tags. If malicious content is injected into an application that escapes special characters and that malicious content uses < and > as HTML tags, those characters are nonetheless not interpreted as HTML tags by the browser if they've been correctly escaped in the application code and in this way the attempted attack is diverted.
The most prominent use of XSS is to steal cookies (source: OWASP HttpOnly) and hijack user sessions, but XSS exploits have been used to expose sensitive information, enable access to privileged services and functionality and deliver malware.
Types of attacks
There are a few methods by which XSS can be manipulated:
| Type | Origin | Description |
|---|---|---|
| Stored | Server | The malicious code is inserted in the application (usually as a link) by the attacker. The code is activated every time a user clicks the link. |
| Reflected | Server | The attacker delivers a malicious link externally from the vulnerable web site application to a user. When clicked, malicious code is sent to the vulnerable web site, which reflects the attack back to the user's browser. |
| DOM-based | Client | The attacker forces the user's browser to render a malicious page. The data in the page itself delivers the cross-site scripting data. |
| Mutated | The attacker injects code that appears safe, but is then rewritten and modified by the browser, while parsing the markup. An example is rebalancing unclosed quotation marks or even adding quotation marks to unquoted parameters. |
Affected environments
The following environments are susceptible to an XSS attack:
- Web servers
- Application servers
- Web application environments
Best practices for prevention
This section describes the top best practices designed to specifically protect your code:
- Sanitize data input in an HTTP request before reflecting it back, ensuring all data is validated, filtered or escaped before echoing anything back to the user, such as the values of query parameters during searches.
- Convert special characters such as
?,&,/,<,>and spaces to their respective HTML or URL encoded equivalents. - Give users the option to disable client-side scripts.
- Redirect invalid requests.
- Detect simultaneous logins, including those from two separate IP addresses, and invalidate those sessions.
- Use and enforce a Content Security Policy (source: Wikipedia) to disable any features that might be manipulated for an XSS attack.
- Read the documentation for any of the libraries referenced in your code to understand which elements allow for embedded HTML.
Cross-site Scripting (XSS)
Unsanitized input from the document location flows into a 'src' script element attribute, where it is used to dynamically construct the HTML page on client side. This may result in a DOM Based Cross-Site Scripting attack (DOMXSS).
⇣ Data Flow
href;
href;
url = window.location.href;
url.indexOf('?');
url.substr(startOfQueryString) : '';
substr(startOfQueryString) : '';
queryString = startOfQueryString > -1 ? url.substr(startOfQueryString) : '';
queryString;
'class.js' + queryString;
✓ Fix Analysis
Details
A cross-site scripting attack occurs when the attacker tricks a legitimate web-based application or site to accept a request as originating from a trusted source.
This is done by escaping the context of the web application; the web application then delivers that data to its users along with other trusted dynamic content, without validating it. The browser unknowingly executes malicious script on the client side (through client-side languages; usually JavaScript or HTML) in order to perform actions that are otherwise typically blocked by the browser's Same Origin Policy.
Injecting malicious code is the most prevalent manner by which XSS is exploited; for this reason, escaping characters in order to prevent this manipulation is the top method for securing code against this vulnerability.
Escaping means that the application is coded to mark key characters, and particularly key characters included in user input, to prevent those characters from being interpreted in a dangerous context. For example, in HTML, < can be coded as < and > can be coded as > in order to be interpreted and displayed as themselves in text, while within the code itself, they are used for HTML tags. If malicious content is injected into an application that escapes special characters and that malicious content uses < and > as HTML tags, those characters are nonetheless not interpreted as HTML tags by the browser if they've been correctly escaped in the application code and in this way the attempted attack is diverted.
The most prominent use of XSS is to steal cookies (source: OWASP HttpOnly) and hijack user sessions, but XSS exploits have been used to expose sensitive information, enable access to privileged services and functionality and deliver malware.
Types of attacks
There are a few methods by which XSS can be manipulated:
| Type | Origin | Description |
|---|---|---|
| Stored | Server | The malicious code is inserted in the application (usually as a link) by the attacker. The code is activated every time a user clicks the link. |
| Reflected | Server | The attacker delivers a malicious link externally from the vulnerable web site application to a user. When clicked, malicious code is sent to the vulnerable web site, which reflects the attack back to the user's browser. |
| DOM-based | Client | The attacker forces the user's browser to render a malicious page. The data in the page itself delivers the cross-site scripting data. |
| Mutated | The attacker injects code that appears safe, but is then rewritten and modified by the browser, while parsing the markup. An example is rebalancing unclosed quotation marks or even adding quotation marks to unquoted parameters. |
Affected environments
The following environments are susceptible to an XSS attack:
- Web servers
- Application servers
- Web application environments
Best practices for prevention
This section describes the top best practices designed to specifically protect your code:
- Sanitize data input in an HTTP request before reflecting it back, ensuring all data is validated, filtered or escaped before echoing anything back to the user, such as the values of query parameters during searches.
- Convert special characters such as
?,&,/,<,>and spaces to their respective HTML or URL encoded equivalents. - Give users the option to disable client-side scripts.
- Redirect invalid requests.
- Detect simultaneous logins, including those from two separate IP addresses, and invalidate those sessions.
- Use and enforce a Content Security Policy (source: Wikipedia) to disable any features that might be manipulated for an XSS attack.
- Read the documentation for any of the libraries referenced in your code to understand which elements allow for embedded HTML.
Cross-site Scripting (XSS)
Unsanitized input from the document location flows into a 'src' script element attribute, where it is used to dynamically construct the HTML page on client side. This may result in a DOM Based Cross-Site Scripting attack (DOMXSS).
⇣ Data Flow
href;
href;
url = window.location.href;
url.indexOf('?');
url.substr(startOfQueryString) : '';
substr(startOfQueryString) : '';
queryString = startOfQueryString > -1 ? url.substr(startOfQueryString) : '';
queryString;
'class.js' + queryString;
✓ Fix Analysis
Details
A cross-site scripting attack occurs when the attacker tricks a legitimate web-based application or site to accept a request as originating from a trusted source.
This is done by escaping the context of the web application; the web application then delivers that data to its users along with other trusted dynamic content, without validating it. The browser unknowingly executes malicious script on the client side (through client-side languages; usually JavaScript or HTML) in order to perform actions that are otherwise typically blocked by the browser's Same Origin Policy.
Injecting malicious code is the most prevalent manner by which XSS is exploited; for this reason, escaping characters in order to prevent this manipulation is the top method for securing code against this vulnerability.
Escaping means that the application is coded to mark key characters, and particularly key characters included in user input, to prevent those characters from being interpreted in a dangerous context. For example, in HTML, < can be coded as < and > can be coded as > in order to be interpreted and displayed as themselves in text, while within the code itself, they are used for HTML tags. If malicious content is injected into an application that escapes special characters and that malicious content uses < and > as HTML tags, those characters are nonetheless not interpreted as HTML tags by the browser if they've been correctly escaped in the application code and in this way the attempted attack is diverted.
The most prominent use of XSS is to steal cookies (source: OWASP HttpOnly) and hijack user sessions, but XSS exploits have been used to expose sensitive information, enable access to privileged services and functionality and deliver malware.
Types of attacks
There are a few methods by which XSS can be manipulated:
| Type | Origin | Description |
|---|---|---|
| Stored | Server | The malicious code is inserted in the application (usually as a link) by the attacker. The code is activated every time a user clicks the link. |
| Reflected | Server | The attacker delivers a malicious link externally from the vulnerable web site application to a user. When clicked, malicious code is sent to the vulnerable web site, which reflects the attack back to the user's browser. |
| DOM-based | Client | The attacker forces the user's browser to render a malicious page. The data in the page itself delivers the cross-site scripting data. |
| Mutated | The attacker injects code that appears safe, but is then rewritten and modified by the browser, while parsing the markup. An example is rebalancing unclosed quotation marks or even adding quotation marks to unquoted parameters. |
Affected environments
The following environments are susceptible to an XSS attack:
- Web servers
- Application servers
- Web application environments
Best practices for prevention
This section describes the top best practices designed to specifically protect your code:
- Sanitize data input in an HTTP request before reflecting it back, ensuring all data is validated, filtered or escaped before echoing anything back to the user, such as the values of query parameters during searches.
- Convert special characters such as
?,&,/,<,>and spaces to their respective HTML or URL encoded equivalents. - Give users the option to disable client-side scripts.
- Redirect invalid requests.
- Detect simultaneous logins, including those from two separate IP addresses, and invalidate those sessions.
- Use and enforce a Content Security Policy (source: Wikipedia) to disable any features that might be manipulated for an XSS attack.
- Read the documentation for any of the libraries referenced in your code to understand which elements allow for embedded HTML.
Cross-site Scripting (XSS)
Unsanitized input from the document location flows into a 'src' script element attribute, where it is used to dynamically construct the HTML page on client side. This may result in a DOM Based Cross-Site Scripting attack (DOMXSS).
⇣ Data Flow
href;
href;
url = window.location.href;
url.indexOf('?');
url.substr(startOfQueryString) : '';
substr(startOfQueryString) : '';
queryString = startOfQueryString > -1 ? url.substr(startOfQueryString) : '';
queryString;
'class.js' + queryString;
✓ Fix Analysis
Details
A cross-site scripting attack occurs when the attacker tricks a legitimate web-based application or site to accept a request as originating from a trusted source.
This is done by escaping the context of the web application; the web application then delivers that data to its users along with other trusted dynamic content, without validating it. The browser unknowingly executes malicious script on the client side (through client-side languages; usually JavaScript or HTML) in order to perform actions that are otherwise typically blocked by the browser's Same Origin Policy.
Injecting malicious code is the most prevalent manner by which XSS is exploited; for this reason, escaping characters in order to prevent this manipulation is the top method for securing code against this vulnerability.
Escaping means that the application is coded to mark key characters, and particularly key characters included in user input, to prevent those characters from being interpreted in a dangerous context. For example, in HTML, < can be coded as < and > can be coded as > in order to be interpreted and displayed as themselves in text, while within the code itself, they are used for HTML tags. If malicious content is injected into an application that escapes special characters and that malicious content uses < and > as HTML tags, those characters are nonetheless not interpreted as HTML tags by the browser if they've been correctly escaped in the application code and in this way the attempted attack is diverted.
The most prominent use of XSS is to steal cookies (source: OWASP HttpOnly) and hijack user sessions, but XSS exploits have been used to expose sensitive information, enable access to privileged services and functionality and deliver malware.
Types of attacks
There are a few methods by which XSS can be manipulated:
| Type | Origin | Description |
|---|---|---|
| Stored | Server | The malicious code is inserted in the application (usually as a link) by the attacker. The code is activated every time a user clicks the link. |
| Reflected | Server | The attacker delivers a malicious link externally from the vulnerable web site application to a user. When clicked, malicious code is sent to the vulnerable web site, which reflects the attack back to the user's browser. |
| DOM-based | Client | The attacker forces the user's browser to render a malicious page. The data in the page itself delivers the cross-site scripting data. |
| Mutated | The attacker injects code that appears safe, but is then rewritten and modified by the browser, while parsing the markup. An example is rebalancing unclosed quotation marks or even adding quotation marks to unquoted parameters. |
Affected environments
The following environments are susceptible to an XSS attack:
- Web servers
- Application servers
- Web application environments
Best practices for prevention
This section describes the top best practices designed to specifically protect your code:
- Sanitize data input in an HTTP request before reflecting it back, ensuring all data is validated, filtered or escaped before echoing anything back to the user, such as the values of query parameters during searches.
- Convert special characters such as
?,&,/,<,>and spaces to their respective HTML or URL encoded equivalents. - Give users the option to disable client-side scripts.
- Redirect invalid requests.
- Detect simultaneous logins, including those from two separate IP addresses, and invalidate those sessions.
- Use and enforce a Content Security Policy (source: Wikipedia) to disable any features that might be manipulated for an XSS attack.
- Read the documentation for any of the libraries referenced in your code to understand which elements allow for embedded HTML.
Path Traversal
Unsanitized input from a command line argument flows into json.dump, where it is used as a path. This may result in a Path Traversal vulnerability and allow an attacker to write arbitrary files.
⇣ Data Flow
sys.argv[2]
sys.argv[2]
sys.argv[2]
control_dir = sys.argv[2]
control_dir, 'input.json'))
control_dir, 'output.json'), indent=2)
pjoin(control_dir, 'output.json'), indent=2)
path, **kwargs):
path, 'w', encoding='utf-8') as f:
open(path, 'w', encoding='utf-8') as f:
f:
f, **kwargs)
json.dump(obj, f, **kwargs)
✓ Fix Analysis
Details
A Directory Traversal attack (also known as path traversal) aims to access files and directories that are stored outside the intended folder. By manipulating files with "dot-dot-slash (../)" sequences and its variations, or by using absolute file paths, it may be possible to access arbitrary files and directories stored on file system, including application source code, configuration, and other critical system files.
Being able to access and manipulate an arbitrary path leads to vulnerabilities when a program is being run with privileges that the user providing the path should not have. A website with a path traversal vulnerability would allow users access to sensitive files on the server hosting it. CLI programs may also be vulnerable to path traversal if they are being ran with elevated privileges (such as with the setuid or setgid flags in Unix systems).
Directory Traversal vulnerabilities can be generally divided into two types:
- Information Disclosure: Allows the attacker to gain information about the folder structure or read the contents of sensitive files on the system.
st is a module for serving static files on web pages, and contains a vulnerability of this type. In our example, we will serve files from the public route.
If an attacker requests the following URL from our server, it will in turn leak the sensitive private key of the root user.
curl http://localhost:8080/public/%2e%2e/%2e%2e/%2e%2e/%2e%2e/%2e%2e/root/.ssh/id_rsa
Note %2e is the URL encoded version of . (dot).
- Writing arbitrary files: Allows the attacker to create or replace existing files. This type of vulnerability is also known as
Zip-Slip.
One way to achieve this is by using a malicious zip archive that holds path traversal filenames. When each filename in the zip archive gets concatenated to the target extraction folder, without validation, the final path ends up outside of the target folder. If an executable or a configuration file is overwritten with a file containing malicious code, the problem can turn into an arbitrary code execution issue quite easily.
The following is an example of a zip archive with one benign file and one malicious file. Extracting the malicious file will result in traversing out of the target folder, ending up in /root/.ssh/ overwriting the authorized_keys file:
2018-04-15 22:04:29 ..... 19 19 good.txt
2018-04-15 22:04:42 ..... 20 20 ../../../../../../root/.ssh/authorized_keys
Path Traversal
Unsanitized input from a command line argument flows into open, where it is used as a path. This may result in a Path Traversal vulnerability and allow an attacker to read arbitrary files.
⇣ Data Flow
sys.argv[2]
sys.argv[2]
sys.argv[2]
control_dir = sys.argv[2]
control_dir, 'input.json'))
pjoin(control_dir, 'input.json'))
path):
path, 'r', encoding='utf-8') as f:
open(path, 'r', encoding='utf-8') as f:
✓ Fix Analysis
Details
A Directory Traversal attack (also known as path traversal) aims to access files and directories that are stored outside the intended folder. By manipulating files with "dot-dot-slash (../)" sequences and its variations, or by using absolute file paths, it may be possible to access arbitrary files and directories stored on file system, including application source code, configuration, and other critical system files.
Being able to access and manipulate an arbitrary path leads to vulnerabilities when a program is being run with privileges that the user providing the path should not have. A website with a path traversal vulnerability would allow users access to sensitive files on the server hosting it. CLI programs may also be vulnerable to path traversal if they are being ran with elevated privileges (such as with the setuid or setgid flags in Unix systems).
Directory Traversal vulnerabilities can be generally divided into two types:
- Information Disclosure: Allows the attacker to gain information about the folder structure or read the contents of sensitive files on the system.
st is a module for serving static files on web pages, and contains a vulnerability of this type. In our example, we will serve files from the public route.
If an attacker requests the following URL from our server, it will in turn leak the sensitive private key of the root user.
curl http://localhost:8080/public/%2e%2e/%2e%2e/%2e%2e/%2e%2e/%2e%2e/root/.ssh/id_rsa
Note %2e is the URL encoded version of . (dot).
- Writing arbitrary files: Allows the attacker to create or replace existing files. This type of vulnerability is also known as
Zip-Slip.
One way to achieve this is by using a malicious zip archive that holds path traversal filenames. When each filename in the zip archive gets concatenated to the target extraction folder, without validation, the final path ends up outside of the target folder. If an executable or a configuration file is overwritten with a file containing malicious code, the problem can turn into an arbitrary code execution issue quite easily.
The following is an example of a zip archive with one benign file and one malicious file. Extracting the malicious file will result in traversing out of the target folder, ending up in /root/.ssh/ overwriting the authorized_keys file:
2018-04-15 22:04:29 ..... 19 19 good.txt
2018-04-15 22:04:42 ..... 20 20 ../../../../../../root/.ssh/authorized_keys
Path Traversal
Unsanitized input from a command line argument flows into open, where it is used as a path. This may result in a Path Traversal vulnerability and allow an attacker to read arbitrary files.
⇣ Data Flow
sys.argv[0] = script_name
sys.argv[0] = script_name
sys.argv[0] = script_name
sys.argv[0] = script_name
script_name, 'rb') as f:
open(script_name, 'rb') as f:
✓ Fix Analysis
Details
A Directory Traversal attack (also known as path traversal) aims to access files and directories that are stored outside the intended folder. By manipulating files with "dot-dot-slash (../)" sequences and its variations, or by using absolute file paths, it may be possible to access arbitrary files and directories stored on file system, including application source code, configuration, and other critical system files.
Being able to access and manipulate an arbitrary path leads to vulnerabilities when a program is being run with privileges that the user providing the path should not have. A website with a path traversal vulnerability would allow users access to sensitive files on the server hosting it. CLI programs may also be vulnerable to path traversal if they are being ran with elevated privileges (such as with the setuid or setgid flags in Unix systems).
Directory Traversal vulnerabilities can be generally divided into two types:
- Information Disclosure: Allows the attacker to gain information about the folder structure or read the contents of sensitive files on the system.
st is a module for serving static files on web pages, and contains a vulnerability of this type. In our example, we will serve files from the public route.
If an attacker requests the following URL from our server, it will in turn leak the sensitive private key of the root user.
curl http://localhost:8080/public/%2e%2e/%2e%2e/%2e%2e/%2e%2e/%2e%2e/root/.ssh/id_rsa
Note %2e is the URL encoded version of . (dot).
- Writing arbitrary files: Allows the attacker to create or replace existing files. This type of vulnerability is also known as
Zip-Slip.
One way to achieve this is by using a malicious zip archive that holds path traversal filenames. When each filename in the zip archive gets concatenated to the target extraction folder, without validation, the final path ends up outside of the target folder. If an executable or a configuration file is overwritten with a file containing malicious code, the problem can turn into an arbitrary code execution issue quite easily.
The following is an example of a zip archive with one benign file and one malicious file. Extracting the malicious file will result in traversing out of the target folder, ending up in /root/.ssh/ overwriting the authorized_keys file:
2018-04-15 22:04:29 ..... 19 19 good.txt
2018-04-15 22:04:42 ..... 20 20 ../../../../../../root/.ssh/authorized_keys
Path Traversal
Unsanitized input from data from a remote resource flows into open, where it is used as a path. This may result in a Path Traversal vulnerability and allow an attacker to write arbitrary files.
⇣ Data Flow
resp.headers.get("content-disposition")
resp.headers.get("content-disposition")
resp.headers.get("content-disposition")
content_disposition = resp.headers.get("content-disposition")
content_disposition:
content_disposition, filename)
content_disposition: str, default_filename: str) -> str:
content_disposition)
cgi.parse_header(content_disposition)
params = cgi.parse_header(content_disposition)
params.get("filename")
params.get("filename")
filename = params.get("filename")
filename:
filename or default_filename
filename or default_filename
filename = parse_content_disposition(content_disposition, filename)
filename)[1]
filename
filename = _get_http_response_filename(resp, link)
filename)
os.path.join(location, filename)
filepath = os.path.join(location, filename)
filepath, "wb") as content_file:
open(filepath, "wb") as content_file:
✓ Fix Analysis
Details
A Directory Traversal attack (also known as path traversal) aims to access files and directories that are stored outside the intended folder. By manipulating files with "dot-dot-slash (../)" sequences and its variations, or by using absolute file paths, it may be possible to access arbitrary files and directories stored on file system, including application source code, configuration, and other critical system files.
Being able to access and manipulate an arbitrary path leads to vulnerabilities when a program is being run with privileges that the user providing the path should not have. A website with a path traversal vulnerability would allow users access to sensitive files on the server hosting it. CLI programs may also be vulnerable to path traversal if they are being ran with elevated privileges (such as with the setuid or setgid flags in Unix systems).
Directory Traversal vulnerabilities can be generally divided into two types:
- Information Disclosure: Allows the attacker to gain information about the folder structure or read the contents of sensitive files on the system.
st is a module for serving static files on web pages, and contains a vulnerability of this type. In our example, we will serve files from the public route.
If an attacker requests the following URL from our server, it will in turn leak the sensitive private key of the root user.
curl http://localhost:8080/public/%2e%2e/%2e%2e/%2e%2e/%2e%2e/%2e%2e/root/.ssh/id_rsa
Note %2e is the URL encoded version of . (dot).
- Writing arbitrary files: Allows the attacker to create or replace existing files. This type of vulnerability is also known as
Zip-Slip.
One way to achieve this is by using a malicious zip archive that holds path traversal filenames. When each filename in the zip archive gets concatenated to the target extraction folder, without validation, the final path ends up outside of the target folder. If an executable or a configuration file is overwritten with a file containing malicious code, the problem can turn into an arbitrary code execution issue quite easily.
The following is an example of a zip archive with one benign file and one malicious file. Extracting the malicious file will result in traversing out of the target folder, ending up in /root/.ssh/ overwriting the authorized_keys file:
2018-04-15 22:04:29 ..... 19 19 good.txt
2018-04-15 22:04:42 ..... 20 20 ../../../../../../root/.ssh/authorized_keys
Path Traversal
Unsanitized input from data from a remote resource flows into open, where it is used as a path. This may result in a Path Traversal vulnerability and allow an attacker to write arbitrary files.
⇣ Data Flow
resp.headers.get("content-disposition")
resp.headers.get("content-disposition")
resp.headers.get("content-disposition")
content_disposition = resp.headers.get("content-disposition")
content_disposition:
content_disposition, filename)
content_disposition: str, default_filename: str) -> str:
content_disposition)
cgi.parse_header(content_disposition)
params = cgi.parse_header(content_disposition)
params.get("filename")
params.get("filename")
filename = params.get("filename")
filename:
filename or default_filename
filename or default_filename
filename = parse_content_disposition(content_disposition, filename)
filename)[1]
filename
filename = _get_http_response_filename(resp, link)
filename)
os.path.join(location, filename)
filepath = os.path.join(location, filename)
filepath, "wb") as content_file:
open(filepath, "wb") as content_file:
✓ Fix Analysis
Details
A Directory Traversal attack (also known as path traversal) aims to access files and directories that are stored outside the intended folder. By manipulating files with "dot-dot-slash (../)" sequences and its variations, or by using absolute file paths, it may be possible to access arbitrary files and directories stored on file system, including application source code, configuration, and other critical system files.
Being able to access and manipulate an arbitrary path leads to vulnerabilities when a program is being run with privileges that the user providing the path should not have. A website with a path traversal vulnerability would allow users access to sensitive files on the server hosting it. CLI programs may also be vulnerable to path traversal if they are being ran with elevated privileges (such as with the setuid or setgid flags in Unix systems).
Directory Traversal vulnerabilities can be generally divided into two types:
- Information Disclosure: Allows the attacker to gain information about the folder structure or read the contents of sensitive files on the system.
st is a module for serving static files on web pages, and contains a vulnerability of this type. In our example, we will serve files from the public route.
If an attacker requests the following URL from our server, it will in turn leak the sensitive private key of the root user.
curl http://localhost:8080/public/%2e%2e/%2e%2e/%2e%2e/%2e%2e/%2e%2e/root/.ssh/id_rsa
Note %2e is the URL encoded version of . (dot).
- Writing arbitrary files: Allows the attacker to create or replace existing files. This type of vulnerability is also known as
Zip-Slip.
One way to achieve this is by using a malicious zip archive that holds path traversal filenames. When each filename in the zip archive gets concatenated to the target extraction folder, without validation, the final path ends up outside of the target folder. If an executable or a configuration file is overwritten with a file containing malicious code, the problem can turn into an arbitrary code execution issue quite easily.
The following is an example of a zip archive with one benign file and one malicious file. Extracting the malicious file will result in traversing out of the target folder, ending up in /root/.ssh/ overwriting the authorized_keys file:
2018-04-15 22:04:29 ..... 19 19 good.txt
2018-04-15 22:04:42 ..... 20 20 ../../../../../../root/.ssh/authorized_keys
Path Traversal
Unsanitized input from an environment variable flows into os.walk, where it is used as a path. This may result in a Path Traversal vulnerability and allow an attacker to read arbitrary files.
⇣ Data Flow
os.environ.get('SETUPTOOLS_LAUNCHER', 'executable')
os.environ.get('SETUPTOOLS_LAUNCHER', 'executable')
launcher = os.environ.get('SETUPTOOLS_LAUNCHER', 'executable')
launcher]
writer_lookup[launcher]
WindowsScriptWriter.best()
ScriptWriter.best().get_args(dist):
ScriptWriter.best().get_args(dist):
args in ScriptWriter.best().get_args(dist):
args)
script_name, contents, mode="t", blockers=()):
script_name, self.script_dir)
script_name)
os.path.join(self.script_dir, script_name)
target = os.path.join(self.script_dir, script_name)
target)
path):
path):
path):
os.walk(path):
✓ Fix Analysis
Details
A Directory Traversal attack (also known as path traversal) aims to access files and directories that are stored outside the intended folder. By manipulating files with "dot-dot-slash (../)" sequences and its variations, or by using absolute file paths, it may be possible to access arbitrary files and directories stored on file system, including application source code, configuration, and other critical system files.
Being able to access and manipulate an arbitrary path leads to vulnerabilities when a program is being run with privileges that the user providing the path should not have. A website with a path traversal vulnerability would allow users access to sensitive files on the server hosting it. CLI programs may also be vulnerable to path traversal if they are being ran with elevated privileges (such as with the setuid or setgid flags in Unix systems).
Directory Traversal vulnerabilities can be generally divided into two types:
- Information Disclosure: Allows the attacker to gain information about the folder structure or read the contents of sensitive files on the system.
st is a module for serving static files on web pages, and contains a vulnerability of this type. In our example, we will serve files from the public route.
If an attacker requests the following URL from our server, it will in turn leak the sensitive private key of the root user.
curl http://localhost:8080/public/%2e%2e/%2e%2e/%2e%2e/%2e%2e/%2e%2e/root/.ssh/id_rsa
Note %2e is the URL encoded version of . (dot).
- Writing arbitrary files: Allows the attacker to create or replace existing files. This type of vulnerability is also known as
Zip-Slip.
One way to achieve this is by using a malicious zip archive that holds path traversal filenames. When each filename in the zip archive gets concatenated to the target extraction folder, without validation, the final path ends up outside of the target folder. If an executable or a configuration file is overwritten with a file containing malicious code, the problem can turn into an arbitrary code execution issue quite easily.
The following is an example of a zip archive with one benign file and one malicious file. Extracting the malicious file will result in traversing out of the target folder, ending up in /root/.ssh/ overwriting the authorized_keys file:
2018-04-15 22:04:29 ..... 19 19 good.txt
2018-04-15 22:04:42 ..... 20 20 ../../../../../../root/.ssh/authorized_keys
Path Traversal
Unsanitized input from an environment variable flows into open, where it is used as a path. This may result in a Path Traversal vulnerability and allow an attacker to write arbitrary files.
⇣ Data Flow
os.environ.get('SETUPTOOLS_LAUNCHER', 'executable')
os.environ.get('SETUPTOOLS_LAUNCHER', 'executable')
launcher = os.environ.get('SETUPTOOLS_LAUNCHER', 'executable')
launcher]
writer_lookup[launcher]
WindowsScriptWriter.best()
ScriptWriter.best().get_args(dist):
ScriptWriter.best().get_args(dist):
args in ScriptWriter.best().get_args(dist):
args)
script_name, contents, mode="t", blockers=()):
script_name, self.script_dir)
script_name)
os.path.join(self.script_dir, script_name)
target = os.path.join(self.script_dir, script_name)
target)
path):
target)
target):
target, "w" + mode) as f:
open(target, "w" + mode) as f:
✓ Fix Analysis
Details
A Directory Traversal attack (also known as path traversal) aims to access files and directories that are stored outside the intended folder. By manipulating files with "dot-dot-slash (../)" sequences and its variations, or by using absolute file paths, it may be possible to access arbitrary files and directories stored on file system, including application source code, configuration, and other critical system files.
Being able to access and manipulate an arbitrary path leads to vulnerabilities when a program is being run with privileges that the user providing the path should not have. A website with a path traversal vulnerability would allow users access to sensitive files on the server hosting it. CLI programs may also be vulnerable to path traversal if they are being ran with elevated privileges (such as with the setuid or setgid flags in Unix systems).
Directory Traversal vulnerabilities can be generally divided into two types:
- Information Disclosure: Allows the attacker to gain information about the folder structure or read the contents of sensitive files on the system.
st is a module for serving static files on web pages, and contains a vulnerability of this type. In our example, we will serve files from the public route.
If an attacker requests the following URL from our server, it will in turn leak the sensitive private key of the root user.
curl http://localhost:8080/public/%2e%2e/%2e%2e/%2e%2e/%2e%2e/%2e%2e/root/.ssh/id_rsa
Note %2e is the URL encoded version of . (dot).
- Writing arbitrary files: Allows the attacker to create or replace existing files. This type of vulnerability is also known as
Zip-Slip.
One way to achieve this is by using a malicious zip archive that holds path traversal filenames. When each filename in the zip archive gets concatenated to the target extraction folder, without validation, the final path ends up outside of the target folder. If an executable or a configuration file is overwritten with a file containing malicious code, the problem can turn into an arbitrary code execution issue quite easily.
The following is an example of a zip archive with one benign file and one malicious file. Extracting the malicious file will result in traversing out of the target folder, ending up in /root/.ssh/ overwriting the authorized_keys file:
2018-04-15 22:04:29 ..... 19 19 good.txt
2018-04-15 22:04:42 ..... 20 20 ../../../../../../root/.ssh/authorized_keys
Path Traversal
Unsanitized input from an environment variable flows into open, where it is used as a path. This may result in a Path Traversal vulnerability and allow an attacker to write arbitrary files.
⇣ Data Flow
os.environ.get('SETUPTOOLS_LAUNCHER', 'executable')
os.environ.get('SETUPTOOLS_LAUNCHER', 'executable')
launcher = os.environ.get('SETUPTOOLS_LAUNCHER', 'executable')
launcher]
writer_lookup[launcher]
WindowsScriptWriter.best()
ScriptWriter.best().get_args(dist):
ScriptWriter.best().get_args(dist):
args in ScriptWriter.best().get_args(dist):
args)
script_name, contents, mode="t", blockers=()):
script_name, self.script_dir)
script_name)
os.path.join(self.script_dir, script_name)
target = os.path.join(self.script_dir, script_name)
target)
path):
target)
target):
target, "w" + mode) as f:
open(target, "w" + mode) as f:
✓ Fix Analysis
Details
A Directory Traversal attack (also known as path traversal) aims to access files and directories that are stored outside the intended folder. By manipulating files with "dot-dot-slash (../)" sequences and its variations, or by using absolute file paths, it may be possible to access arbitrary files and directories stored on file system, including application source code, configuration, and other critical system files.
Being able to access and manipulate an arbitrary path leads to vulnerabilities when a program is being run with privileges that the user providing the path should not have. A website with a path traversal vulnerability would allow users access to sensitive files on the server hosting it. CLI programs may also be vulnerable to path traversal if they are being ran with elevated privileges (such as with the setuid or setgid flags in Unix systems).
Directory Traversal vulnerabilities can be generally divided into two types:
- Information Disclosure: Allows the attacker to gain information about the folder structure or read the contents of sensitive files on the system.
st is a module for serving static files on web pages, and contains a vulnerability of this type. In our example, we will serve files from the public route.
If an attacker requests the following URL from our server, it will in turn leak the sensitive private key of the root user.
curl http://localhost:8080/public/%2e%2e/%2e%2e/%2e%2e/%2e%2e/%2e%2e/root/.ssh/id_rsa
Note %2e is the URL encoded version of . (dot).
- Writing arbitrary files: Allows the attacker to create or replace existing files. This type of vulnerability is also known as
Zip-Slip.
One way to achieve this is by using a malicious zip archive that holds path traversal filenames. When each filename in the zip archive gets concatenated to the target extraction folder, without validation, the final path ends up outside of the target folder. If an executable or a configuration file is overwritten with a file containing malicious code, the problem can turn into an arbitrary code execution issue quite easily.
The following is an example of a zip archive with one benign file and one malicious file. Extracting the malicious file will result in traversing out of the target folder, ending up in /root/.ssh/ overwriting the authorized_keys file:
2018-04-15 22:04:29 ..... 19 19 good.txt
2018-04-15 22:04:42 ..... 20 20 ../../../../../../root/.ssh/authorized_keys
Path Traversal
Unsanitized input from an environment variable flows into os.unlink, where it is used as a path. This may result in a Path Traversal vulnerability and allow an attacker to remove arbitrary files.
⇣ Data Flow
os.environ.get('SETUPTOOLS_LAUNCHER', 'executable')
os.environ.get('SETUPTOOLS_LAUNCHER', 'executable')
launcher = os.environ.get('SETUPTOOLS_LAUNCHER', 'executable')
launcher]
writer_lookup[launcher]
WindowsScriptWriter.best()
ScriptWriter.best().get_args(dist):
ScriptWriter.best().get_args(dist):
args in ScriptWriter.best().get_args(dist):
args)
script_name, contents, mode="t", blockers=()):
script_name, self.script_dir)
script_name)
os.path.join(self.script_dir, script_name)
target = os.path.join(self.script_dir, script_name)
target)
path):
target)
target):
target)
os.unlink(target)
✓ Fix Analysis
Details
A Directory Traversal attack (also known as path traversal) aims to access files and directories that are stored outside the intended folder. By manipulating files with "dot-dot-slash (../)" sequences and its variations, or by using absolute file paths, it may be possible to access arbitrary files and directories stored on file system, including application source code, configuration, and other critical system files.
Being able to access and manipulate an arbitrary path leads to vulnerabilities when a program is being run with privileges that the user providing the path should not have. A website with a path traversal vulnerability would allow users access to sensitive files on the server hosting it. CLI programs may also be vulnerable to path traversal if they are being ran with elevated privileges (such as with the setuid or setgid flags in Unix systems).
Directory Traversal vulnerabilities can be generally divided into two types:
- Information Disclosure: Allows the attacker to gain information about the folder structure or read the contents of sensitive files on the system.
st is a module for serving static files on web pages, and contains a vulnerability of this type. In our example, we will serve files from the public route.
If an attacker requests the following URL from our server, it will in turn leak the sensitive private key of the root user.
curl http://localhost:8080/public/%2e%2e/%2e%2e/%2e%2e/%2e%2e/%2e%2e/root/.ssh/id_rsa
Note %2e is the URL encoded version of . (dot).
- Writing arbitrary files: Allows the attacker to create or replace existing files. This type of vulnerability is also known as
Zip-Slip.
One way to achieve this is by using a malicious zip archive that holds path traversal filenames. When each filename in the zip archive gets concatenated to the target extraction folder, without validation, the final path ends up outside of the target folder. If an executable or a configuration file is overwritten with a file containing malicious code, the problem can turn into an arbitrary code execution issue quite easily.
The following is an example of a zip archive with one benign file and one malicious file. Extracting the malicious file will result in traversing out of the target folder, ending up in /root/.ssh/ overwriting the authorized_keys file:
2018-04-15 22:04:29 ..... 19 19 good.txt
2018-04-15 22:04:42 ..... 20 20 ../../../../../../root/.ssh/authorized_keys
Path Traversal
Unsanitized input from an environment variable flows into os.chmod, where it is used as a path. This may result in a Path Traversal vulnerability and allow an attacker to manipulate arbitrary files.
⇣ Data Flow
os.environ.get('SETUPTOOLS_LAUNCHER', 'executable')
os.environ.get('SETUPTOOLS_LAUNCHER', 'executable')
launcher = os.environ.get('SETUPTOOLS_LAUNCHER', 'executable')
launcher]
writer_lookup[launcher]
WindowsScriptWriter.best()
ScriptWriter.best().get_args(dist):
ScriptWriter.best().get_args(dist):
args in ScriptWriter.best().get_args(dist):
args)
script_name, contents, mode="t", blockers=()):
script_name, self.script_dir)
script_name)
os.path.join(self.script_dir, script_name)
target = os.path.join(self.script_dir, script_name)
target)
path):
target)
target):
target, "w" + mode) as f:
target, 0o777 - mask)
path, mode):
path, mode)
path, mode)
_chmod(path, mode)
✓ Fix Analysis
Details
A Directory Traversal attack (also known as path traversal) aims to access files and directories that are stored outside the intended folder. By manipulating files with "dot-dot-slash (../)" sequences and its variations, or by using absolute file paths, it may be possible to access arbitrary files and directories stored on file system, including application source code, configuration, and other critical system files.
Being able to access and manipulate an arbitrary path leads to vulnerabilities when a program is being run with privileges that the user providing the path should not have. A website with a path traversal vulnerability would allow users access to sensitive files on the server hosting it. CLI programs may also be vulnerable to path traversal if they are being ran with elevated privileges (such as with the setuid or setgid flags in Unix systems).
Directory Traversal vulnerabilities can be generally divided into two types:
- Information Disclosure: Allows the attacker to gain information about the folder structure or read the contents of sensitive files on the system.
st is a module for serving static files on web pages, and contains a vulnerability of this type. In our example, we will serve files from the public route.
If an attacker requests the following URL from our server, it will in turn leak the sensitive private key of the root user.
curl http://localhost:8080/public/%2e%2e/%2e%2e/%2e%2e/%2e%2e/%2e%2e/root/.ssh/id_rsa
Note %2e is the URL encoded version of . (dot).
- Writing arbitrary files: Allows the attacker to create or replace existing files. This type of vulnerability is also known as
Zip-Slip.
One way to achieve this is by using a malicious zip archive that holds path traversal filenames. When each filename in the zip archive gets concatenated to the target extraction folder, without validation, the final path ends up outside of the target folder. If an executable or a configuration file is overwritten with a file containing malicious code, the problem can turn into an arbitrary code execution issue quite easily.
The following is an example of a zip archive with one benign file and one malicious file. Extracting the malicious file will result in traversing out of the target folder, ending up in /root/.ssh/ overwriting the authorized_keys file:
2018-04-15 22:04:29 ..... 19 19 good.txt
2018-04-15 22:04:42 ..... 20 20 ../../../../../../root/.ssh/authorized_keys
Path Traversal
Unsanitized input from a command line argument flows into shutil.move, where it is used as a path. This may result in a Path Traversal vulnerability and allow an attacker to remove arbitrary files.
⇣ Data Flow
parser.parse_args()
parser.parse_args()
args = parser.parse_args()
args.source_dir, args.out_dir)
args.source_dir, args.out_dir)
source_dir='.', dest=None, system=None):
source_dir)
source_dir, dest or 'dist')
source_dir, system['build-backend'], system.get('backend-path')
Pep517HookCaller(
hooks = Pep517HookCaller( source_dir, system['build-backend'], system.get('backend-path') )
hooks.subprocess_runner(quiet_subprocess_runner):
hooks, env, dest)
hooks, env, dest):
hooks.get_requires_for_build_wheel({})
hooks.prepare_metadata_for_build_wheel(td, {})
hooks.prepare_metadata_for_build_wheel(td, {})
filename = hooks.prepare_metadata_for_build_wheel(td, {})
filename)
os.path.join(td, filename)
source = os.path.join(td, filename)
source, os.path.join(dest, os.path.basename(filename)))
shutil.move(source, os.path.join(dest, os.path.basename(filename)))
✓ Fix Analysis
Details
A Directory Traversal attack (also known as path traversal) aims to access files and directories that are stored outside the intended folder. By manipulating files with "dot-dot-slash (../)" sequences and its variations, or by using absolute file paths, it may be possible to access arbitrary files and directories stored on file system, including application source code, configuration, and other critical system files.
Being able to access and manipulate an arbitrary path leads to vulnerabilities when a program is being run with privileges that the user providing the path should not have. A website with a path traversal vulnerability would allow users access to sensitive files on the server hosting it. CLI programs may also be vulnerable to path traversal if they are being ran with elevated privileges (such as with the setuid or setgid flags in Unix systems).
Directory Traversal vulnerabilities can be generally divided into two types:
- Information Disclosure: Allows the attacker to gain information about the folder structure or read the contents of sensitive files on the system.
st is a module for serving static files on web pages, and contains a vulnerability of this type. In our example, we will serve files from the public route.
If an attacker requests the following URL from our server, it will in turn leak the sensitive private key of the root user.
curl http://localhost:8080/public/%2e%2e/%2e%2e/%2e%2e/%2e%2e/%2e%2e/root/.ssh/id_rsa
Note %2e is the URL encoded version of . (dot).
- Writing arbitrary files: Allows the attacker to create or replace existing files. This type of vulnerability is also known as
Zip-Slip.
One way to achieve this is by using a malicious zip archive that holds path traversal filenames. When each filename in the zip archive gets concatenated to the target extraction folder, without validation, the final path ends up outside of the target folder. If an executable or a configuration file is overwritten with a file containing malicious code, the problem can turn into an arbitrary code execution issue quite easily.
The following is an example of a zip archive with one benign file and one malicious file. Extracting the malicious file will result in traversing out of the target folder, ending up in /root/.ssh/ overwriting the authorized_keys file:
2018-04-15 22:04:29 ..... 19 19 good.txt
2018-04-15 22:04:42 ..... 20 20 ../../../../../../root/.ssh/authorized_keys
Path Traversal
Unsanitized input from an environment variable flows into open, where it is used as a path. This may result in a Path Traversal vulnerability and allow an attacker to read arbitrary files.
⇣ Data Flow
os.environ.get('UNIXCONFDIR', '/etc')
os.environ.get('UNIXCONFDIR', '/etc')
_UNIXCONFDIR = os.environ.get('UNIXCONFDIR', '/etc')
_UNIXCONFDIR, _OS_RELEASE_BASENAME)
_UNIXCONFDIR)
_UNIXCONFDIR, basename)
os.path.join(_UNIXCONFDIR, basename)
filepath = os.path.join(_UNIXCONFDIR, basename)
filepath)
filepath):
filepath) as fp:
open(filepath) as fp:
✓ Fix Analysis
Details
A Directory Traversal attack (also known as path traversal) aims to access files and directories that are stored outside the intended folder. By manipulating files with "dot-dot-slash (../)" sequences and its variations, or by using absolute file paths, it may be possible to access arbitrary files and directories stored on file system, including application source code, configuration, and other critical system files.
Being able to access and manipulate an arbitrary path leads to vulnerabilities when a program is being run with privileges that the user providing the path should not have. A website with a path traversal vulnerability would allow users access to sensitive files on the server hosting it. CLI programs may also be vulnerable to path traversal if they are being ran with elevated privileges (such as with the setuid or setgid flags in Unix systems).
Directory Traversal vulnerabilities can be generally divided into two types:
- Information Disclosure: Allows the attacker to gain information about the folder structure or read the contents of sensitive files on the system.
st is a module for serving static files on web pages, and contains a vulnerability of this type. In our example, we will serve files from the public route.
If an attacker requests the following URL from our server, it will in turn leak the sensitive private key of the root user.
curl http://localhost:8080/public/%2e%2e/%2e%2e/%2e%2e/%2e%2e/%2e%2e/root/.ssh/id_rsa
Note %2e is the URL encoded version of . (dot).
- Writing arbitrary files: Allows the attacker to create or replace existing files. This type of vulnerability is also known as
Zip-Slip.
One way to achieve this is by using a malicious zip archive that holds path traversal filenames. When each filename in the zip archive gets concatenated to the target extraction folder, without validation, the final path ends up outside of the target folder. If an executable or a configuration file is overwritten with a file containing malicious code, the problem can turn into an arbitrary code execution issue quite easily.
The following is an example of a zip archive with one benign file and one malicious file. Extracting the malicious file will result in traversing out of the target folder, ending up in /root/.ssh/ overwriting the authorized_keys file:
2018-04-15 22:04:29 ..... 19 19 good.txt
2018-04-15 22:04:42 ..... 20 20 ../../../../../../root/.ssh/authorized_keys
Path Traversal
Unsanitized input from an environment variable flows into open, where it is used as a path. This may result in a Path Traversal vulnerability and allow an attacker to read arbitrary files.
⇣ Data Flow
os.environ.get('UNIXCONFDIR', '/etc')
os.environ.get('UNIXCONFDIR', '/etc')
_UNIXCONFDIR = os.environ.get('UNIXCONFDIR', '/etc')
_UNIXCONFDIR, _OS_RELEASE_BASENAME)
_UNIXCONFDIR)
_UNIXCONFDIR, basename)
os.path.join(_UNIXCONFDIR, basename)
filepath = os.path.join(_UNIXCONFDIR, basename)
filepath)
filepath):
filepath
self.distro_release_file = filepath
self.distro_release_file:
self.distro_release_file)
filepath) as fp:
open(filepath) as fp:
✓ Fix Analysis
Details
A Directory Traversal attack (also known as path traversal) aims to access files and directories that are stored outside the intended folder. By manipulating files with "dot-dot-slash (../)" sequences and its variations, or by using absolute file paths, it may be possible to access arbitrary files and directories stored on file system, including application source code, configuration, and other critical system files.
Being able to access and manipulate an arbitrary path leads to vulnerabilities when a program is being run with privileges that the user providing the path should not have. A website with a path traversal vulnerability would allow users access to sensitive files on the server hosting it. CLI programs may also be vulnerable to path traversal if they are being ran with elevated privileges (such as with the setuid or setgid flags in Unix systems).
Directory Traversal vulnerabilities can be generally divided into two types:
- Information Disclosure: Allows the attacker to gain information about the folder structure or read the contents of sensitive files on the system.
st is a module for serving static files on web pages, and contains a vulnerability of this type. In our example, we will serve files from the public route.
If an attacker requests the following URL from our server, it will in turn leak the sensitive private key of the root user.
curl http://localhost:8080/public/%2e%2e/%2e%2e/%2e%2e/%2e%2e/%2e%2e/root/.ssh/id_rsa
Note %2e is the URL encoded version of . (dot).
- Writing arbitrary files: Allows the attacker to create or replace existing files. This type of vulnerability is also known as
Zip-Slip.
One way to achieve this is by using a malicious zip archive that holds path traversal filenames. When each filename in the zip archive gets concatenated to the target extraction folder, without validation, the final path ends up outside of the target folder. If an executable or a configuration file is overwritten with a file containing malicious code, the problem can turn into an arbitrary code execution issue quite easily.
The following is an example of a zip archive with one benign file and one malicious file. Extracting the malicious file will result in traversing out of the target folder, ending up in /root/.ssh/ overwriting the authorized_keys file:
2018-04-15 22:04:29 ..... 19 19 good.txt
2018-04-15 22:04:42 ..... 20 20 ../../../../../../root/.ssh/authorized_keys
Path Traversal
Unsanitized input from an environment variable flows into open, where it is used as a path. This may result in a Path Traversal vulnerability and allow an attacker to read arbitrary files.
⇣ Data Flow
os.environ.get("PYTHONSTARTUP")
os.environ.get("PYTHONSTARTUP")
startup = os.environ.get("PYTHONSTARTUP")
startup and os.path.isfile(startup):
startup):
startup) as f:
open(startup) as f:
✓ Fix Analysis
Details
A Directory Traversal attack (also known as path traversal) aims to access files and directories that are stored outside the intended folder. By manipulating files with "dot-dot-slash (../)" sequences and its variations, or by using absolute file paths, it may be possible to access arbitrary files and directories stored on file system, including application source code, configuration, and other critical system files.
Being able to access and manipulate an arbitrary path leads to vulnerabilities when a program is being run with privileges that the user providing the path should not have. A website with a path traversal vulnerability would allow users access to sensitive files on the server hosting it. CLI programs may also be vulnerable to path traversal if they are being ran with elevated privileges (such as with the setuid or setgid flags in Unix systems).
Directory Traversal vulnerabilities can be generally divided into two types:
- Information Disclosure: Allows the attacker to gain information about the folder structure or read the contents of sensitive files on the system.
st is a module for serving static files on web pages, and contains a vulnerability of this type. In our example, we will serve files from the public route.
If an attacker requests the following URL from our server, it will in turn leak the sensitive private key of the root user.
curl http://localhost:8080/public/%2e%2e/%2e%2e/%2e%2e/%2e%2e/%2e%2e/root/.ssh/id_rsa
Note %2e is the URL encoded version of . (dot).
- Writing arbitrary files: Allows the attacker to create or replace existing files. This type of vulnerability is also known as
Zip-Slip.
One way to achieve this is by using a malicious zip archive that holds path traversal filenames. When each filename in the zip archive gets concatenated to the target extraction folder, without validation, the final path ends up outside of the target folder. If an executable or a configuration file is overwritten with a file containing malicious code, the problem can turn into an arbitrary code execution issue quite easily.
The following is an example of a zip archive with one benign file and one malicious file. Extracting the malicious file will result in traversing out of the target folder, ending up in /root/.ssh/ overwriting the authorized_keys file:
2018-04-15 22:04:29 ..... 19 19 good.txt
2018-04-15 22:04:42 ..... 20 20 ../../../../../../root/.ssh/authorized_keys
Path Traversal
Unsanitized input from an environment variable flows into open, where it is used as a path. This may result in a Path Traversal vulnerability and allow an attacker to read arbitrary files.
⇣ Data Flow
os.environ.get(variable_name)
os.environ.get(variable_name)
rv = os.environ.get(variable_name)
rv:
rv, silent=silent)
filename: str | os.PathLike[str], silent: bool = False
filename)
os.path.join(self.root_path, filename)
filename = os.path.join(self.root_path, filename)
filename
d.__file__ = filename
filename, mode="rb") as config_file:
open(filename, mode="rb") as config_file:
✓ Fix Analysis
Details
A Directory Traversal attack (also known as path traversal) aims to access files and directories that are stored outside the intended folder. By manipulating files with "dot-dot-slash (../)" sequences and its variations, or by using absolute file paths, it may be possible to access arbitrary files and directories stored on file system, including application source code, configuration, and other critical system files.
Being able to access and manipulate an arbitrary path leads to vulnerabilities when a program is being run with privileges that the user providing the path should not have. A website with a path traversal vulnerability would allow users access to sensitive files on the server hosting it. CLI programs may also be vulnerable to path traversal if they are being ran with elevated privileges (such as with the setuid or setgid flags in Unix systems).
Directory Traversal vulnerabilities can be generally divided into two types:
- Information Disclosure: Allows the attacker to gain information about the folder structure or read the contents of sensitive files on the system.
st is a module for serving static files on web pages, and contains a vulnerability of this type. In our example, we will serve files from the public route.
If an attacker requests the following URL from our server, it will in turn leak the sensitive private key of the root user.
curl http://localhost:8080/public/%2e%2e/%2e%2e/%2e%2e/%2e%2e/%2e%2e/root/.ssh/id_rsa
Note %2e is the URL encoded version of . (dot).
- Writing arbitrary files: Allows the attacker to create or replace existing files. This type of vulnerability is also known as
Zip-Slip.
One way to achieve this is by using a malicious zip archive that holds path traversal filenames. When each filename in the zip archive gets concatenated to the target extraction folder, without validation, the final path ends up outside of the target folder. If an executable or a configuration file is overwritten with a file containing malicious code, the problem can turn into an arbitrary code execution issue quite easily.
The following is an example of a zip archive with one benign file and one malicious file. Extracting the malicious file will result in traversing out of the target folder, ending up in /root/.ssh/ overwriting the authorized_keys file:
2018-04-15 22:04:29 ..... 19 19 good.txt
2018-04-15 22:04:42 ..... 20 20 ../../../../../../root/.ssh/authorized_keys
Path Traversal
Unsanitized input from a command line argument flows into shutil.move, where it is used as a path. This may result in a Path Traversal vulnerability and allow an attacker to write arbitrary files.
⇣ Data Flow
parser.parse_args())
parser.parse_args())
args):
args.source or not args.binary else None,
args.binary else None,
args.binary or not args.source else None,
args.source else None,
args.source_dir, dist, args.out_dir)
args.source_dir, dist, args.out_dir)
source_dir, dist, dest=None, system=None):
source_dir)
source_dir):
source_dir, dest or 'dist')
os.path.join(source_dir, dest or 'dist')
dest = os.path.join(source_dir, dest or 'dist')
dest)
dest)
dest):
dest, os.path.basename(filename)))
os.path.join(dest, os.path.basename(filename)))
shutil.move(source, os.path.join(dest, os.path.basename(filename)))
✓ Fix Analysis
Details
A Directory Traversal attack (also known as path traversal) aims to access files and directories that are stored outside the intended folder. By manipulating files with "dot-dot-slash (../)" sequences and its variations, or by using absolute file paths, it may be possible to access arbitrary files and directories stored on file system, including application source code, configuration, and other critical system files.
Being able to access and manipulate an arbitrary path leads to vulnerabilities when a program is being run with privileges that the user providing the path should not have. A website with a path traversal vulnerability would allow users access to sensitive files on the server hosting it. CLI programs may also be vulnerable to path traversal if they are being ran with elevated privileges (such as with the setuid or setgid flags in Unix systems).
Directory Traversal vulnerabilities can be generally divided into two types:
- Information Disclosure: Allows the attacker to gain information about the folder structure or read the contents of sensitive files on the system.
st is a module for serving static files on web pages, and contains a vulnerability of this type. In our example, we will serve files from the public route.
If an attacker requests the following URL from our server, it will in turn leak the sensitive private key of the root user.
curl http://localhost:8080/public/%2e%2e/%2e%2e/%2e%2e/%2e%2e/%2e%2e/root/.ssh/id_rsa
Note %2e is the URL encoded version of . (dot).
- Writing arbitrary files: Allows the attacker to create or replace existing files. This type of vulnerability is also known as
Zip-Slip.
One way to achieve this is by using a malicious zip archive that holds path traversal filenames. When each filename in the zip archive gets concatenated to the target extraction folder, without validation, the final path ends up outside of the target folder. If an executable or a configuration file is overwritten with a file containing malicious code, the problem can turn into an arbitrary code execution issue quite easily.
The following is an example of a zip archive with one benign file and one malicious file. Extracting the malicious file will result in traversing out of the target folder, ending up in /root/.ssh/ overwriting the authorized_keys file:
2018-04-15 22:04:29 ..... 19 19 good.txt
2018-04-15 22:04:42 ..... 20 20 ../../../../../../root/.ssh/authorized_keys
Path Traversal
Unsanitized input from a command line argument flows into shutil.move, where it is used as a path. This may result in a Path Traversal vulnerability and allow an attacker to write arbitrary files.
⇣ Data Flow
parser.parse_args())
parser.parse_args())
args):
args.source or not args.binary else None,
args.binary else None,
args.binary or not args.source else None,
args.source else None,
args.source_dir, dist, args.out_dir)
args.source_dir, dist, args.out_dir)
source_dir, dist, dest=None, system=None):
source_dir)
source_dir):
source_dir, dest or 'dist')
os.path.join(source_dir, dest or 'dist')
dest = os.path.join(source_dir, dest or 'dist')
dest)
dest)
dest):
dest, os.path.basename(filename)))
os.path.join(dest, os.path.basename(filename)))
shutil.move(source, os.path.join(dest, os.path.basename(filename)))
✓ Fix Analysis
Details
A Directory Traversal attack (also known as path traversal) aims to access files and directories that are stored outside the intended folder. By manipulating files with "dot-dot-slash (../)" sequences and its variations, or by using absolute file paths, it may be possible to access arbitrary files and directories stored on file system, including application source code, configuration, and other critical system files.
Being able to access and manipulate an arbitrary path leads to vulnerabilities when a program is being run with privileges that the user providing the path should not have. A website with a path traversal vulnerability would allow users access to sensitive files on the server hosting it. CLI programs may also be vulnerable to path traversal if they are being ran with elevated privileges (such as with the setuid or setgid flags in Unix systems).
Directory Traversal vulnerabilities can be generally divided into two types:
- Information Disclosure: Allows the attacker to gain information about the folder structure or read the contents of sensitive files on the system.
st is a module for serving static files on web pages, and contains a vulnerability of this type. In our example, we will serve files from the public route.
If an attacker requests the following URL from our server, it will in turn leak the sensitive private key of the root user.
curl http://localhost:8080/public/%2e%2e/%2e%2e/%2e%2e/%2e%2e/%2e%2e/root/.ssh/id_rsa
Note %2e is the URL encoded version of . (dot).
- Writing arbitrary files: Allows the attacker to create or replace existing files. This type of vulnerability is also known as
Zip-Slip.
One way to achieve this is by using a malicious zip archive that holds path traversal filenames. When each filename in the zip archive gets concatenated to the target extraction folder, without validation, the final path ends up outside of the target folder. If an executable or a configuration file is overwritten with a file containing malicious code, the problem can turn into an arbitrary code execution issue quite easily.
The following is an example of a zip archive with one benign file and one malicious file. Extracting the malicious file will result in traversing out of the target folder, ending up in /root/.ssh/ overwriting the authorized_keys file:
2018-04-15 22:04:29 ..... 19 19 good.txt
2018-04-15 22:04:42 ..... 20 20 ../../../../../../root/.ssh/authorized_keys
Command Injection
Unsanitized input from a command line argument flows into subprocess.check_call, where it is used as a shell command. This may result in a Command Injection vulnerability.
⇣ Data Flow
parser.parse_args()
parser.parse_args()
args = parser.parse_args()
args.source_dir, args.out_dir)
args.source_dir, args.out_dir)
source_dir='.', dest=None, system=None):
source_dir)
load_system(source_dir)
system or load_system(source_dir)
system = system or load_system(source_dir)
system)
system.get('backend-path')
system['build-backend'], system.get('backend-path')
system['requires'])
system['requires'])
reqs):
reqs:
reqs)
reqs)
list(reqs)
[ sys.executable, '-m', 'pip', 'install', '--ignore-installed', '--prefix', self.path] + list(reqs)
cmd = [ sys.executable, '-m', 'pip', 'install', '--ignore-installed', '--prefix', self.path] + list(reqs)
cmd,
check_call(
✓ Fix Analysis
Details
With an OS command injection attack a web application user can pass commands directly to the system shell, attached to a legitimate request. These commands can then be executed on the application server, potentially leading to harmful consequences, including data exposure or deletion. Like code injection attacks, command injection attacks are essentially a failure of data validation. Unlike code injection attacks, which introduce new code, command injection attacks use existing system functions, often taking advantage of the application's unnecessarily high privilege level, increasing the risk of serious harm and reputational damage.
Best practices for prevention
- Never trust user input. Assume any input may transmit harmful values.
- Adopt the principle of least privilege: No application should have a greater access level than needed to run its required tasks.
- Control user access policies on a task-by-task basis.
- Don't pass user input directly to the system; use libraries or APIs that lack system access.
- Where shell commands must be passed, escape values using functions like shlex for Python, or escapeshellarg() for PHP.
- Sanitize user input with regular expressions to define permitted characters along with maximum string length.
- Convert special characters such as
& | ; $ > < \ !before passing to the server. - Whitelist permitted commands and validate user responses against these expectations.
- Remember that code injection can take place on multiple fronts: GET and POST requests, but also cookies and HTTP headers.
- Ensure up-to-date patching across all systems to remediate known vulnerabilities.
- Educate all team members on safer data handling procedures to prevent attacks.
Command Injection
Unsanitized input from a command line argument flows into subprocess.check_call, where it is used as a shell command. This may result in a Command Injection vulnerability.
⇣ Data Flow
parser.parse_args())
parser.parse_args())
args):
args.source or not args.binary else None,
args.binary else None,
args.binary or not args.source else None,
args.source else None,
args.source_dir, dist, args.out_dir)
args.source_dir, dist, args.out_dir)
source_dir, dist, dest=None, system=None):
source_dir)
source_dir):
source_dir, 'pyproject.toml')
os.path.join(source_dir, 'pyproject.toml')
pyproject = os.path.join(source_dir, 'pyproject.toml')
pyproject, encoding="utf-8") as f:
io.open(pyproject, encoding="utf-8") as f:
f:
f)
toml_load(f)
pyproject_data = toml_load(f)
pyproject_data['build-system']
pyproject_data['build-system']
system or load_system(source_dir)
system = system or load_system(source_dir)
system)
system):
system.get('backend-path')
system['build-backend'], system.get('backend-path')
system['requires'])
system['requires'])
reqs):
reqs:
reqs)
reqs)
list(reqs)
[ sys.executable, '-m', 'pip', 'install', '--ignore-installed', '--prefix', self.path] + list(reqs)
cmd = [ sys.executable, '-m', 'pip', 'install', '--ignore-installed', '--prefix', self.path] + list(reqs)
cmd,
check_call(
✓ Fix Analysis
Details
With an OS command injection attack a web application user can pass commands directly to the system shell, attached to a legitimate request. These commands can then be executed on the application server, potentially leading to harmful consequences, including data exposure or deletion. Like code injection attacks, command injection attacks are essentially a failure of data validation. Unlike code injection attacks, which introduce new code, command injection attacks use existing system functions, often taking advantage of the application's unnecessarily high privilege level, increasing the risk of serious harm and reputational damage.
Best practices for prevention
- Never trust user input. Assume any input may transmit harmful values.
- Adopt the principle of least privilege: No application should have a greater access level than needed to run its required tasks.
- Control user access policies on a task-by-task basis.
- Don't pass user input directly to the system; use libraries or APIs that lack system access.
- Where shell commands must be passed, escape values using functions like shlex for Python, or escapeshellarg() for PHP.
- Sanitize user input with regular expressions to define permitted characters along with maximum string length.
- Convert special characters such as
& | ; $ > < \ !before passing to the server. - Whitelist permitted commands and validate user responses against these expectations.
- Remember that code injection can take place on multiple fronts: GET and POST requests, but also cookies and HTTP headers.
- Ensure up-to-date patching across all systems to remediate known vulnerabilities.
- Educate all team members on safer data handling procedures to prevent attacks.
Command Injection
Unsanitized input from a command line argument flows into subprocess.check_call, where it is used as a shell command. This may result in a Command Injection vulnerability.
⇣ Data Flow
parser.parse_args())
parser.parse_args())
args):
args.source or not args.binary else None,
args.binary else None,
args.binary or not args.source else None,
args.source else None,
args.source_dir, dist, args.out_dir)
args.source_dir, dist, args.out_dir)
source_dir, dist, dest=None, system=None):
source_dir)
source_dir):
source_dir, 'pyproject.toml')
os.path.join(source_dir, 'pyproject.toml')
pyproject = os.path.join(source_dir, 'pyproject.toml')
pyproject, encoding="utf-8") as f:
io.open(pyproject, encoding="utf-8") as f:
f:
f)
toml_load(f)
pyproject_data = toml_load(f)
pyproject_data['build-system']
pyproject_data['build-system']
system or load_system(source_dir)
system = system or load_system(source_dir)
system)
system):
system.get('backend-path')
system['build-backend'], system.get('backend-path')
system['requires'])
system['requires'])
reqs):
reqs:
reqs)
reqs)
list(reqs)
[ sys.executable, '-m', 'pip', 'install', '--ignore-installed', '--prefix', self.path] + list(reqs)
cmd = [ sys.executable, '-m', 'pip', 'install', '--ignore-installed', '--prefix', self.path] + list(reqs)
cmd,
check_call(
✓ Fix Analysis
Details
With an OS command injection attack a web application user can pass commands directly to the system shell, attached to a legitimate request. These commands can then be executed on the application server, potentially leading to harmful consequences, including data exposure or deletion. Like code injection attacks, command injection attacks are essentially a failure of data validation. Unlike code injection attacks, which introduce new code, command injection attacks use existing system functions, often taking advantage of the application's unnecessarily high privilege level, increasing the risk of serious harm and reputational damage.
Best practices for prevention
- Never trust user input. Assume any input may transmit harmful values.
- Adopt the principle of least privilege: No application should have a greater access level than needed to run its required tasks.
- Control user access policies on a task-by-task basis.
- Don't pass user input directly to the system; use libraries or APIs that lack system access.
- Where shell commands must be passed, escape values using functions like shlex for Python, or escapeshellarg() for PHP.
- Sanitize user input with regular expressions to define permitted characters along with maximum string length.
- Convert special characters such as
& | ; $ > < \ !before passing to the server. - Whitelist permitted commands and validate user responses against these expectations.
- Remember that code injection can take place on multiple fronts: GET and POST requests, but also cookies and HTTP headers.
- Ensure up-to-date patching across all systems to remediate known vulnerabilities.
- Educate all team members on safer data handling procedures to prevent attacks.
Command Injection
Unsanitized input from a command line argument flows into subprocess.check_call, where it is used as a shell command. This may result in a Command Injection vulnerability.
⇣ Data Flow
ap.parse_args(argv)
ap.parse_args(argv)
args = ap.parse_args(argv)
args.source_dir)
args.source_dir)
source_dir):
source_dir, 'pyproject.toml')
source_dir, backend, backend_path)
Pep517HookCaller(source_dir, backend, backend_path)
hooks = Pep517HookCaller(source_dir, backend, backend_path)
hooks, requires)
hooks, build_sys_requires):
hooks.get_requires_for_build_sdist({})
hooks.get_requires_for_build_sdist({})
reqs = hooks.get_requires_for_build_sdist({})
reqs)
reqs)
reqs):
reqs:
reqs)
reqs)
list(reqs)
[ sys.executable, '-m', 'pip', 'install', '--ignore-installed', '--prefix', self.path] + list(reqs)
cmd = [ sys.executable, '-m', 'pip', 'install', '--ignore-installed', '--prefix', self.path] + list(reqs)
cmd,
check_call(
✓ Fix Analysis
Details
With an OS command injection attack a web application user can pass commands directly to the system shell, attached to a legitimate request. These commands can then be executed on the application server, potentially leading to harmful consequences, including data exposure or deletion. Like code injection attacks, command injection attacks are essentially a failure of data validation. Unlike code injection attacks, which introduce new code, command injection attacks use existing system functions, often taking advantage of the application's unnecessarily high privilege level, increasing the risk of serious harm and reputational damage.
Best practices for prevention
- Never trust user input. Assume any input may transmit harmful values.
- Adopt the principle of least privilege: No application should have a greater access level than needed to run its required tasks.
- Control user access policies on a task-by-task basis.
- Don't pass user input directly to the system; use libraries or APIs that lack system access.
- Where shell commands must be passed, escape values using functions like shlex for Python, or escapeshellarg() for PHP.
- Sanitize user input with regular expressions to define permitted characters along with maximum string length.
- Convert special characters such as
& | ; $ > < \ !before passing to the server. - Whitelist permitted commands and validate user responses against these expectations.
- Remember that code injection can take place on multiple fronts: GET and POST requests, but also cookies and HTTP headers.
- Ensure up-to-date patching across all systems to remediate known vulnerabilities.
- Educate all team members on safer data handling procedures to prevent attacks.
Command Injection
Unsanitized input from a command line argument flows into subprocess.check_call, where it is used as a shell command. This may result in a Command Injection vulnerability.
⇣ Data Flow
ap.parse_args(argv)
ap.parse_args(argv)
args = ap.parse_args(argv)
args.source_dir)
args.source_dir)
source_dir):
source_dir, 'pyproject.toml')
source_dir, backend, backend_path)
Pep517HookCaller(source_dir, backend, backend_path)
hooks = Pep517HookCaller(source_dir, backend, backend_path)
hooks, requires)
hooks, build_sys_requires):
hooks, requires)
hooks, build_sys_requires):
hooks.get_requires_for_build_wheel({})
hooks.get_requires_for_build_wheel({})
reqs = hooks.get_requires_for_build_wheel({})
reqs)
reqs)
reqs):
reqs:
reqs)
reqs)
list(reqs)
[ sys.executable, '-m', 'pip', 'install', '--ignore-installed', '--prefix', self.path] + list(reqs)
cmd = [ sys.executable, '-m', 'pip', 'install', '--ignore-installed', '--prefix', self.path] + list(reqs)
cmd,
check_call(
✓ Fix Analysis
Details
With an OS command injection attack a web application user can pass commands directly to the system shell, attached to a legitimate request. These commands can then be executed on the application server, potentially leading to harmful consequences, including data exposure or deletion. Like code injection attacks, command injection attacks are essentially a failure of data validation. Unlike code injection attacks, which introduce new code, command injection attacks use existing system functions, often taking advantage of the application's unnecessarily high privilege level, increasing the risk of serious harm and reputational damage.
Best practices for prevention
- Never trust user input. Assume any input may transmit harmful values.
- Adopt the principle of least privilege: No application should have a greater access level than needed to run its required tasks.
- Control user access policies on a task-by-task basis.
- Don't pass user input directly to the system; use libraries or APIs that lack system access.
- Where shell commands must be passed, escape values using functions like shlex for Python, or escapeshellarg() for PHP.
- Sanitize user input with regular expressions to define permitted characters along with maximum string length.
- Convert special characters such as
& | ; $ > < \ !before passing to the server. - Whitelist permitted commands and validate user responses against these expectations.
- Remember that code injection can take place on multiple fronts: GET and POST requests, but also cookies and HTTP headers.
- Ensure up-to-date patching across all systems to remediate known vulnerabilities.
- Educate all team members on safer data handling procedures to prevent attacks.
Command Injection
Unsanitized input from an environment variable flows into subprocess.Popen, where it is used as a shell command. This may result in a Command Injection vulnerability.
⇣ Data Flow
os.environ.get("PAGER", None) or "").strip()
os.environ.get("PAGER", None) or "").strip()
os.environ.get("PAGER", None) or "").strip()
(os.environ.get("PAGER", None) or "").strip()
pager_cmd = (os.environ.get("PAGER", None) or "").strip()
pager_cmd:
pager_cmd, color)
cmd: str, color: t.Optional[bool]) -> None:
cmd.rsplit("/", 1)[-1].split()
cmd, shell=True, stdin=subprocess.PIPE, env=env)
subprocess.Popen(cmd, shell=True, stdin=subprocess.PIPE, env=env)
✓ Fix Analysis
Details
With an OS command injection attack a web application user can pass commands directly to the system shell, attached to a legitimate request. These commands can then be executed on the application server, potentially leading to harmful consequences, including data exposure or deletion. Like code injection attacks, command injection attacks are essentially a failure of data validation. Unlike code injection attacks, which introduce new code, command injection attacks use existing system functions, often taking advantage of the application's unnecessarily high privilege level, increasing the risk of serious harm and reputational damage.
Best practices for prevention
- Never trust user input. Assume any input may transmit harmful values.
- Adopt the principle of least privilege: No application should have a greater access level than needed to run its required tasks.
- Control user access policies on a task-by-task basis.
- Don't pass user input directly to the system; use libraries or APIs that lack system access.
- Where shell commands must be passed, escape values using functions like shlex for Python, or escapeshellarg() for PHP.
- Sanitize user input with regular expressions to define permitted characters along with maximum string length.
- Convert special characters such as
& | ; $ > < \ !before passing to the server. - Whitelist permitted commands and validate user responses against these expectations.
- Remember that code injection can take place on multiple fronts: GET and POST requests, but also cookies and HTTP headers.
- Ensure up-to-date patching across all systems to remediate known vulnerabilities.
- Educate all team members on safer data handling procedures to prevent attacks.
Command Injection
Unsanitized input from an environment variable flows into subprocess.Popen, where it is used as a shell command. This may result in a Command Injection vulnerability.
⇣ Data Flow
os.environ.get(key)
os.environ.get(key)
rv = os.environ.get(key)
rv:
rv
editor = self.get_editor()
editor} "{filename}"', env=environ, shell=True)
f'{editor} "{filename}"', env=environ, shell=True)
subprocess.Popen(f'{editor} "{filename}"', env=environ, shell=True)
✓ Fix Analysis
Details
With an OS command injection attack a web application user can pass commands directly to the system shell, attached to a legitimate request. These commands can then be executed on the application server, potentially leading to harmful consequences, including data exposure or deletion. Like code injection attacks, command injection attacks are essentially a failure of data validation. Unlike code injection attacks, which introduce new code, command injection attacks use existing system functions, often taking advantage of the application's unnecessarily high privilege level, increasing the risk of serious harm and reputational damage.
Best practices for prevention
- Never trust user input. Assume any input may transmit harmful values.
- Adopt the principle of least privilege: No application should have a greater access level than needed to run its required tasks.
- Control user access policies on a task-by-task basis.
- Don't pass user input directly to the system; use libraries or APIs that lack system access.
- Where shell commands must be passed, escape values using functions like shlex for Python, or escapeshellarg() for PHP.
- Sanitize user input with regular expressions to define permitted characters along with maximum string length.
- Convert special characters such as
& | ; $ > < \ !before passing to the server. - Whitelist permitted commands and validate user responses against these expectations.
- Remember that code injection can take place on multiple fronts: GET and POST requests, but also cookies and HTTP headers.
- Ensure up-to-date patching across all systems to remediate known vulnerabilities.
- Educate all team members on safer data handling procedures to prevent attacks.
Command Injection
Unsanitized input from an environment variable flows into os.system, where it is used as a shell command. This may result in a Command Injection vulnerability.
⇣ Data Flow
os.environ.get("PAGER", None) or "").strip()
os.environ.get("PAGER", None) or "").strip()
os.environ.get("PAGER", None) or "").strip()
(os.environ.get("PAGER", None) or "").strip()
pager_cmd = (os.environ.get("PAGER", None) or "").strip()
pager_cmd:
pager_cmd, color)
cmd: str, color: t.Optional[bool]
cmd} "{filename}"')
f'{cmd} "{filename}"')
os.system(f'{cmd} "{filename}"')
✓ Fix Analysis
Details
With an OS command injection attack a web application user can pass commands directly to the system shell, attached to a legitimate request. These commands can then be executed on the application server, potentially leading to harmful consequences, including data exposure or deletion. Like code injection attacks, command injection attacks are essentially a failure of data validation. Unlike code injection attacks, which introduce new code, command injection attacks use existing system functions, often taking advantage of the application's unnecessarily high privilege level, increasing the risk of serious harm and reputational damage.
Best practices for prevention
- Never trust user input. Assume any input may transmit harmful values.
- Adopt the principle of least privilege: No application should have a greater access level than needed to run its required tasks.
- Control user access policies on a task-by-task basis.
- Don't pass user input directly to the system; use libraries or APIs that lack system access.
- Where shell commands must be passed, escape values using functions like shlex for Python, or escapeshellarg() for PHP.
- Sanitize user input with regular expressions to define permitted characters along with maximum string length.
- Convert special characters such as
& | ; $ > < \ !before passing to the server. - Whitelist permitted commands and validate user responses against these expectations.
- Remember that code injection can take place on multiple fronts: GET and POST requests, but also cookies and HTTP headers.
- Ensure up-to-date patching across all systems to remediate known vulnerabilities.
- Educate all team members on safer data handling procedures to prevent attacks.
Code Injection
Unsanitized input from a command line argument flows into exec, where it is executed as Python code. This may result in a Code Injection vulnerability.
⇣ Data Flow
sys.argv[0] = script_name
sys.argv[0] = script_name
sys.argv[0] = script_name
sys.argv[0] = script_name
script_name, 'rb') as f:
open(script_name, 'rb') as f:
f:
f.read(), g)
f.read(), g)
exec(f.read(), g)
✓ Fix Analysis
Details
A secure code injection attack occurs when the attacker exploits an existing input processing vulnerability, passing special characters and code directly to a web-based application or site. The code is then executed, potentially granting the user system access to export sensitive data, to install malware, or even to move laterally and to exploit other systems in the trusted internal network environment. While code injection attacks can take place in several ways, the common factor is allowing the user to submit executable code to the application. The most common forms of code injection are SQL injection (server side) and cross-site scripting (XSS) (client side).
Best practices for prevention
- Never trust user input. Assume any input may transmit harmful values.
- Apply least privilege principle (for example, limit users to read only wherever possible).
- Avoid passing raw user input directly to functions; use parameterized queries to extract data first.
- Sanitize user input strings of special characters such as ?, &, /, <, >, and quotation marks.
- Use whitelisting of known good values.
- Validate user input against expected response types.
- Escape shell commands with functions such as shlex for Python, or escapeshellarg for PHP.
- Remember that code injection can take place on multiple fronts: GET and POST requests, but also cookies and HTTP headers.
- Ensure up-to-date patching across all systems to remediate known vulnerabilities so these cannot be exploited by code injection.
- Educate all team members on safe data handling procedures to prevent attacks.
Code Injection
Unsanitized input from an environment variable flows into importlib.import_module, where it is executed as Python code. This may result in a Code Injection vulnerability.
⇣ Data Flow
os.environ['PEP517_BUILD_BACKEND']
os.environ['PEP517_BUILD_BACKEND']
ep = os.environ['PEP517_BUILD_BACKEND']
ep.partition(':')
ep.partition(':')
mod_path, _, obj_path = ep.partition(':')
mod_path)
import_module(mod_path)
✓ Fix Analysis
Details
A secure code injection attack occurs when the attacker exploits an existing input processing vulnerability, passing special characters and code directly to a web-based application or site. The code is then executed, potentially granting the user system access to export sensitive data, to install malware, or even to move laterally and to exploit other systems in the trusted internal network environment. While code injection attacks can take place in several ways, the common factor is allowing the user to submit executable code to the application. The most common forms of code injection are SQL injection (server side) and cross-site scripting (XSS) (client side).
Best practices for prevention
- Never trust user input. Assume any input may transmit harmful values.
- Apply least privilege principle (for example, limit users to read only wherever possible).
- Avoid passing raw user input directly to functions; use parameterized queries to extract data first.
- Sanitize user input strings of special characters such as ?, &, /, <, >, and quotation marks.
- Use whitelisting of known good values.
- Validate user input against expected response types.
- Escape shell commands with functions such as shlex for Python, or escapeshellarg for PHP.
- Remember that code injection can take place on multiple fronts: GET and POST requests, but also cookies and HTTP headers.
- Ensure up-to-date patching across all systems to remediate known vulnerabilities so these cannot be exploited by code injection.
- Educate all team members on safe data handling procedures to prevent attacks.
Code Injection
Unsanitized input from a command line argument flows into access of the globals() dictionary, where it is executed as Python code. This may result in a Code Injection vulnerability.
⇣ Data Flow
sys.argv[1]
sys.argv[1]
sys.argv[1]
hook_name = sys.argv[1]
hook_name not in HOOK_NAMES:
hook_name]
✓ Fix Analysis
Details
A secure code injection attack occurs when the attacker exploits an existing input processing vulnerability, passing special characters and code directly to a web-based application or site. The code is then executed, potentially granting the user system access to export sensitive data, to install malware, or even to move laterally and to exploit other systems in the trusted internal network environment. While code injection attacks can take place in several ways, the common factor is allowing the user to submit executable code to the application. The most common forms of code injection are SQL injection (server side) and cross-site scripting (XSS) (client side).
Best practices for prevention
- Never trust user input. Assume any input may transmit harmful values.
- Apply least privilege principle (for example, limit users to read only wherever possible).
- Avoid passing raw user input directly to functions; use parameterized queries to extract data first.
- Sanitize user input strings of special characters such as ?, &, /, <, >, and quotation marks.
- Use whitelisting of known good values.
- Validate user input against expected response types.
- Escape shell commands with functions such as shlex for Python, or escapeshellarg for PHP.
- Remember that code injection can take place on multiple fronts: GET and POST requests, but also cookies and HTTP headers.
- Ensure up-to-date patching across all systems to remediate known vulnerabilities so these cannot be exploited by code injection.
- Educate all team members on safe data handling procedures to prevent attacks.
Code Injection
Unsanitized input from an environment variable flows into exec, where it is executed as Python code. This may result in a Code Injection vulnerability.
⇣ Data Flow
os.environ.get(variable_name)
os.environ.get(variable_name)
rv = os.environ.get(variable_name)
rv:
rv, silent=silent)
filename: str | os.PathLike[str], silent: bool = False
filename)
os.path.join(self.root_path, filename)
filename = os.path.join(self.root_path, filename)
filename
d.__file__ = filename
filename, mode="rb") as config_file:
filename, "exec"), d.__dict__)
compile(config_file.read(), filename, "exec"), d.__dict__)
exec(compile(config_file.read(), filename, "exec"), d.__dict__)
✓ Fix Analysis
Details
A secure code injection attack occurs when the attacker exploits an existing input processing vulnerability, passing special characters and code directly to a web-based application or site. The code is then executed, potentially granting the user system access to export sensitive data, to install malware, or even to move laterally and to exploit other systems in the trusted internal network environment. While code injection attacks can take place in several ways, the common factor is allowing the user to submit executable code to the application. The most common forms of code injection are SQL injection (server side) and cross-site scripting (XSS) (client side).
Best practices for prevention
- Never trust user input. Assume any input may transmit harmful values.
- Apply least privilege principle (for example, limit users to read only wherever possible).
- Avoid passing raw user input directly to functions; use parameterized queries to extract data first.
- Sanitize user input strings of special characters such as ?, &, /, <, >, and quotation marks.
- Use whitelisting of known good values.
- Validate user input against expected response types.
- Escape shell commands with functions such as shlex for Python, or escapeshellarg for PHP.
- Remember that code injection can take place on multiple fronts: GET and POST requests, but also cookies and HTTP headers.
- Ensure up-to-date patching across all systems to remediate known vulnerabilities so these cannot be exploited by code injection.
- Educate all team members on safe data handling procedures to prevent attacks.
Code Injection
Unsanitized input from an environment variable flows into eval, where it is executed as Python code. This may result in a Code Injection vulnerability.
⇣ Data Flow
os.environ.get("PYTHONSTARTUP")
os.environ.get("PYTHONSTARTUP")
startup = os.environ.get("PYTHONSTARTUP")
startup and os.path.isfile(startup):
startup):
startup) as f:
startup, "exec"), ctx)
compile(f.read(), startup, "exec"), ctx)
eval(compile(f.read(), startup, "exec"), ctx)
✓ Fix Analysis
Details
A secure code injection attack occurs when the attacker exploits an existing input processing vulnerability, passing special characters and code directly to a web-based application or site. The code is then executed, potentially granting the user system access to export sensitive data, to install malware, or even to move laterally and to exploit other systems in the trusted internal network environment. While code injection attacks can take place in several ways, the common factor is allowing the user to submit executable code to the application. The most common forms of code injection are SQL injection (server side) and cross-site scripting (XSS) (client side).
Best practices for prevention
- Never trust user input. Assume any input may transmit harmful values.
- Apply least privilege principle (for example, limit users to read only wherever possible).
- Avoid passing raw user input directly to functions; use parameterized queries to extract data first.
- Sanitize user input strings of special characters such as ?, &, /, <, >, and quotation marks.
- Use whitelisting of known good values.
- Validate user input against expected response types.
- Escape shell commands with functions such as shlex for Python, or escapeshellarg for PHP.
- Remember that code injection can take place on multiple fronts: GET and POST requests, but also cookies and HTTP headers.
- Ensure up-to-date patching across all systems to remediate known vulnerabilities so these cannot be exploited by code injection.
- Educate all team members on safe data handling procedures to prevent attacks.
Arbitrary File Write via Archive Extraction (Tar Slip)
Calling extractall to extract all files from a tar file without sanitization. This may result files outside destination directory to be overwritten, resulting in an arbitrary file write.
⇣ Data Flow
archive.extractall(dest_dir)
✓ Fix Analysis
Details
Zip Slip is a form of directory traversal that can be exploited by extracting files from an archive. The premise of the directory traversal vulnerability is that an attacker can gain access to parts of the file system outside of the target folder in which they should reside. The attacker can then overwrite executable files and either invoke them remotely or wait for the system or user to call them, thus achieving remote command execution on the victim’s machine. The vulnerability can also cause damage by overwriting configuration files or other sensitive resources, and can be exploited on both client (user) machines and servers.
Example
The following is an example of a zip archive with one benign file and one malicious file. Extracting the malicious file will result in traversing out of the target folder, ending up in /root/.ssh/ overwriting the authorized_keys file:
2018-04-15 22:04:29 ..... 19 19 good.txt
2018-04-15 22:04:42 ..... 20 20 ../../../../../../root/.ssh/authorized_keys
Debug Mode Enabled
Running the application in debug mode (debug flag is set to True in run) is a security risk if the application is accessible by untrusted parties.
⇣ Data Flow
True)
app.run(debug=True)
✓ Fix Analysis
Details
When debugging, it may be necessary to report detailed information to a developer. However, if the debugging code is not disabled when the application is operating in a production environment, then this sensitive information may be exposed to attackers.
Command Injection
Unsanitized input from a command line argument flows into subprocess.call, where it is used as a shell command. This may result in a Command Injection vulnerability.
⇣ Data Flow
sys.argv[0]
sys.argv[0]
sys.argv[0]
py_script = sys.argv[0]
py_script)
py_script}.exe")
py_script)
os.path.abspath(py_script)
py_script = os.path.abspath(py_script)
py_script)
rv.append(py_script)
rv.extend(args)
rv
args = _get_args_for_reloading()
args, env=new_environ, close_fds=False)
subprocess.call(args, env=new_environ, close_fds=False)
✓ Fix Analysis
Details
With an OS command injection attack a web application user can pass commands directly to the system shell, attached to a legitimate request. These commands can then be executed on the application server, potentially leading to harmful consequences, including data exposure or deletion. Like code injection attacks, command injection attacks are essentially a failure of data validation. Unlike code injection attacks, which introduce new code, command injection attacks use existing system functions, often taking advantage of the application's unnecessarily high privilege level, increasing the risk of serious harm and reputational damage.
Best practices for prevention
- Never trust user input. Assume any input may transmit harmful values.
- Adopt the principle of least privilege: No application should have a greater access level than needed to run its required tasks.
- Control user access policies on a task-by-task basis.
- Don't pass user input directly to the system; use libraries or APIs that lack system access.
- Where shell commands must be passed, escape values using functions like shlex for Python, or escapeshellarg() for PHP.
- Sanitize user input with regular expressions to define permitted characters along with maximum string length.
- Convert special characters such as
& | ; $ > < \ !before passing to the server. - Whitelist permitted commands and validate user responses against these expectations.
- Remember that code injection can take place on multiple fronts: GET and POST requests, but also cookies and HTTP headers.
- Ensure up-to-date patching across all systems to remediate known vulnerabilities.
- Educate all team members on safer data handling procedures to prevent attacks.
Command Injection
Unsanitized input from an environment variable flows into subprocess.check_call, where it is used as a shell command. This may result in a Command Injection vulnerability.
⇣ Data Flow
os.environ["VISUAL"]
os.environ["VISUAL"]
editor = self._determine_editor(options)
editor, fname])
[editor, fname])
subprocess.check_call([editor, fname])
✓ Fix Analysis
Details
With an OS command injection attack a web application user can pass commands directly to the system shell, attached to a legitimate request. These commands can then be executed on the application server, potentially leading to harmful consequences, including data exposure or deletion. Like code injection attacks, command injection attacks are essentially a failure of data validation. Unlike code injection attacks, which introduce new code, command injection attacks use existing system functions, often taking advantage of the application's unnecessarily high privilege level, increasing the risk of serious harm and reputational damage.
Best practices for prevention
- Never trust user input. Assume any input may transmit harmful values.
- Adopt the principle of least privilege: No application should have a greater access level than needed to run its required tasks.
- Control user access policies on a task-by-task basis.
- Don't pass user input directly to the system; use libraries or APIs that lack system access.
- Where shell commands must be passed, escape values using functions like shlex for Python, or escapeshellarg() for PHP.
- Sanitize user input with regular expressions to define permitted characters along with maximum string length.
- Convert special characters such as
& | ; $ > < \ !before passing to the server. - Whitelist permitted commands and validate user responses against these expectations.
- Remember that code injection can take place on multiple fronts: GET and POST requests, but also cookies and HTTP headers.
- Ensure up-to-date patching across all systems to remediate known vulnerabilities.
- Educate all team members on safer data handling procedures to prevent attacks.
Command Injection
Unsanitized input from an environment variable flows into subprocess.check_output, where it is used as a shell command. This may result in a Command Injection vulnerability.
⇣ Data Flow
os.environ.get("ProgramFiles(x86)") or os.environ.get("ProgramFiles")
os.environ.get("ProgramFiles(x86)") or os.environ.get("ProgramFiles")
os.environ.get("ProgramFiles(x86)") or os.environ.get("ProgramFiles")
root = os.environ.get("ProgramFiles(x86)") or os.environ.get("ProgramFiles")
root:
root, "Microsoft Visual Studio", "Installer", "vswhere.exe"),
os.path.join(root, "Microsoft Visual Studio", "Installer", "vswhere.exe"),
[ os.path.join(root, "Microsoft Visual Studio", "Installer", "vswhere.exe"), "-latest", "-prerelease", "-requires", "Microsoft.VisualStudio.Component.VC.Tools.x86.x64", "-property", "installationPath", "-products", "*", ], encoding="mbcs", errors="strict").strip()
subprocess.check_output([
✓ Fix Analysis
Details
With an OS command injection attack a web application user can pass commands directly to the system shell, attached to a legitimate request. These commands can then be executed on the application server, potentially leading to harmful consequences, including data exposure or deletion. Like code injection attacks, command injection attacks are essentially a failure of data validation. Unlike code injection attacks, which introduce new code, command injection attacks use existing system functions, often taking advantage of the application's unnecessarily high privilege level, increasing the risk of serious harm and reputational damage.
Best practices for prevention
- Never trust user input. Assume any input may transmit harmful values.
- Adopt the principle of least privilege: No application should have a greater access level than needed to run its required tasks.
- Control user access policies on a task-by-task basis.
- Don't pass user input directly to the system; use libraries or APIs that lack system access.
- Where shell commands must be passed, escape values using functions like shlex for Python, or escapeshellarg() for PHP.
- Sanitize user input with regular expressions to define permitted characters along with maximum string length.
- Convert special characters such as
& | ; $ > < \ !before passing to the server. - Whitelist permitted commands and validate user responses against these expectations.
- Remember that code injection can take place on multiple fronts: GET and POST requests, but also cookies and HTTP headers.
- Ensure up-to-date patching across all systems to remediate known vulnerabilities.
- Educate all team members on safer data handling procedures to prevent attacks.
Code Injection
Unsanitized input from a command line argument flows into exec, where it is executed as Python code. This may result in a Code Injection vulnerability.
⇣ Data Flow
sys.argv[1]
sys.argv[1]
sys.argv[1]
script_name = sys.argv[1]
script_name,
script_name) as fid:
open_(script_name) as fid:
fid:
fid.read()
fid.read()
script = fid.read()
script.replace('\\r\\n', '\\n')
script.replace('\\r\\n', '\\n')
norm_script = script.replace('\\r\\n', '\\n')
norm_script, script_name, 'exec')
compile(norm_script, script_name, 'exec')
code = compile(norm_script, script_name, 'exec')
code, namespace)
exec(code, namespace)
✓ Fix Analysis
Details
A secure code injection attack occurs when the attacker exploits an existing input processing vulnerability, passing special characters and code directly to a web-based application or site. The code is then executed, potentially granting the user system access to export sensitive data, to install malware, or even to move laterally and to exploit other systems in the trusted internal network environment. While code injection attacks can take place in several ways, the common factor is allowing the user to submit executable code to the application. The most common forms of code injection are SQL injection (server side) and cross-site scripting (XSS) (client side).
Best practices for prevention
- Never trust user input. Assume any input may transmit harmful values.
- Apply least privilege principle (for example, limit users to read only wherever possible).
- Avoid passing raw user input directly to functions; use parameterized queries to extract data first.
- Sanitize user input strings of special characters such as ?, &, /, <, >, and quotation marks.
- Use whitelisting of known good values.
- Validate user input against expected response types.
- Escape shell commands with functions such as shlex for Python, or escapeshellarg for PHP.
- Remember that code injection can take place on multiple fronts: GET and POST requests, but also cookies and HTTP headers.
- Ensure up-to-date patching across all systems to remediate known vulnerabilities so these cannot be exploited by code injection.
- Educate all team members on safe data handling procedures to prevent attacks.
Code Injection
Unsanitized input from an environment variable flows into __import__, where it is executed as Python code. This may result in a Code Injection vulnerability.
⇣ Data Flow
os.environ.get('_PYTHON_SYSCONFIGDATA_NAME',
os.environ.get('_PYTHON_SYSCONFIGDATA_NAME',
name = os.environ.get('_PYTHON_SYSCONFIGDATA_NAME', '_sysconfigdata_{abi}_{platform}_{multiarch}'.format( abi=sys.abiflags, platform=sys.platform, multiarch=getattr(sys.implementation, '_multiarch', ''), ))
name, globals(), locals(), ['build_time_vars'], 0)
__import__(name, globals(), locals(), ['build_time_vars'], 0)
✓ Fix Analysis
Details
A secure code injection attack occurs when the attacker exploits an existing input processing vulnerability, passing special characters and code directly to a web-based application or site. The code is then executed, potentially granting the user system access to export sensitive data, to install malware, or even to move laterally and to exploit other systems in the trusted internal network environment. While code injection attacks can take place in several ways, the common factor is allowing the user to submit executable code to the application. The most common forms of code injection are SQL injection (server side) and cross-site scripting (XSS) (client side).
Best practices for prevention
- Never trust user input. Assume any input may transmit harmful values.
- Apply least privilege principle (for example, limit users to read only wherever possible).
- Avoid passing raw user input directly to functions; use parameterized queries to extract data first.
- Sanitize user input strings of special characters such as ?, &, /, <, >, and quotation marks.
- Use whitelisting of known good values.
- Validate user input against expected response types.
- Escape shell commands with functions such as shlex for Python, or escapeshellarg for PHP.
- Remember that code injection can take place on multiple fronts: GET and POST requests, but also cookies and HTTP headers.
- Ensure up-to-date patching across all systems to remediate known vulnerabilities so these cannot be exploited by code injection.
- Educate all team members on safe data handling procedures to prevent attacks.
Insecure Temporary File
Use of tempfile.mktemp is deprecated and poses a security risk
⇣ Data Flow
mktemp(".py")
✓ Fix Analysis
Details
Creating temporary files can allow an attacker to guess the filename, and potentially create a file with the same filename with less restrictive access rights and gain access to the contents written by the application.
Best practices for prevention
- Use more robust solutions to create file names like UUIDs or strong random values
References
Insecure Temporary File
Use of tempfile.mktemp is deprecated and poses a security risk
⇣ Data Flow
mktemp()
✓ Fix Analysis
Details
Creating temporary files can allow an attacker to guess the filename, and potentially create a file with the same filename with less restrictive access rights and gain access to the contents written by the application.
Best practices for prevention
- Use more robust solutions to create file names like UUIDs or strong random values
References
Arbitrary File Write via Archive Extraction (Tar Slip)
Unsanitized input from an opened tar file flows into extractfile, where it is used to extract a file from a tar archive. This may result files outside destination directory to be overwritten, resulting in an arbitrary file write.
⇣ Data Flow
tarfile.open(filename, mode, encoding="utf-8")
tarfile.open(filename, mode, encoding="utf-8")
tar = tarfile.open(filename, mode, encoding="utf-8")
tar.getmembers()])
tar.getmembers():
tar.getmembers():
member in tar.getmembers():
member.name
member.isdir():
member.issym():
member)
tar.extractfile(member)
✓ Fix Analysis
Details
Zip Slip is a form of directory traversal that can be exploited by extracting files from an archive. The premise of the directory traversal vulnerability is that an attacker can gain access to parts of the file system outside of the target folder in which they should reside. The attacker can then overwrite executable files and either invoke them remotely or wait for the system or user to call them, thus achieving remote command execution on the victim’s machine. The vulnerability can also cause damage by overwriting configuration files or other sensitive resources, and can be exploited on both client (user) machines and servers.
Example
The following is an example of a zip archive with one benign file and one malicious file. Extracting the malicious file will result in traversing out of the target folder, ending up in /root/.ssh/ overwriting the authorized_keys file:
2018-04-15 22:04:29 ..... 19 19 good.txt
2018-04-15 22:04:42 ..... 20 20 ../../../../../../root/.ssh/authorized_keys
Server Information Exposure
The stack trace from an exception flows into response_class and is leaked to the user. This may disclose sensitive server information to the attackers.
⇣ Data Flow
as e: rv = self.handle_user_exception(e)
as e: rv = self.handle_user_exception(e)
e)
e: Exception
e, BadRequestKeyError) and (
e, HTTPException) and not self.trap_http_exception(e):
e):
e, request.blueprints)
e) # type: ignore[no-any-return]
self.ensure_sync(handler)(e) # type: ignore[no-any-return]
rv = self.handle_user_exception(e)
rv)
rv: ft.ResponseReturnValue | HTTPException,
rv)
rv: ft.ResponseReturnValue) -> Response:
rv, tuple):
rv is None:
rv, self.response_class):
rv, (str, bytes, bytearray)) or isinstance(rv, cabc.Iterator):
rv, cabc.Iterator):
rv,
self.response_class(
✓ Fix Analysis
Details
When a command to your site or application fails, it should do so gracefully, meaning that the user is informed that there has been a problem, rather than experiencing erratic behavior, such as crashing, hanging, or returning a 404 or similar generic error page.
In some cases, developers include information in an error message to help pinpoint the source of an error; these may include username, password, application path, stack values, and other internal details. When this weakness is present, if these logs are accessible to an attacker, it may give them clues as to the inner workings of the app, helping them plan a focused attack. For example, clues revealing SQL database details may help plan an SQL injection attack.
Best practices for prevention
- Keep error messages to the barest minimum of helpful information that users absolutely need to know.
- Use consistent error messages that do not give attackers clues that they might be on the right track to a successful attack, such as "File not found" or "User name does not exist".
- Ensure that debugging information is removed from code prior to release.
- Create clear policy for the types of errors that must be logged, which messages will be displayed to users, and which details will be logged for later alerting and debugging.
- When logging error details, never include sensitive information such as passwords.
- Implement naming conventions that will help you flag and defend sensitive information.
- Use dynamic (white box) test techniques to identify conditions that could cause errors and failures and test thoroughly to ensure that the code performs gracefully without revealing sensitive data under these stress conditions.
Use of Password Hash With Insufficient Computational Effort
hashlib.sha1 is insecure. Consider changing it to a secure hashing algorithm.
⇣ Data Flow
hashlib.sha1(x).hexdigest()
✓ Fix Analysis
Details
Sensitive information should never be stored in plain text, since this makes it very easy for unauthorized users, whether malicious insiders or outside attackers, to access. Hashing methods are used to make stored passwords and other sensitive data unreadable to users. For example, when a password is defined for the first time, it is hashed and then stored. The next time that user attempts to log on, the password they enter is hashed following the same procedure and compared with the stored value. In this way, the original password never needs to be stored in the system.
Hashing is a one-way scheme, meaning a hashed password cannot be reverse engineered. However, if an outdated or custom programmed hashing scheme is used, it becomes simple for an attacker with powerful modern computing power to gain access to the hashes used. This opens up access to all stored password information, leading to breached security. Therefore, it is essential for developers to understand modern, secure password hashing techniques.
Best practices for prevention
- Use strong standard algorithms for hashing rather than simpler but outdated methods or DIY hashing schemes, which may have inherent weaknesses.
- Use modular design for all code dealing with hashing so it can be swapped out as security standards change over time.
- Use salting in combination with hashing (While this places more demands on resources, it is an essential step for tighter security.).
- Implement zero-trust architecture to ensure that access to password data is granted only for legitimate business purposes.
- Increase developer awareness of current standards in data security and cryptography.
Use of Password Hash With Insufficient Computational Effort
hashlib.sha1 is insecure. Consider changing it to a secure hashing algorithm.
⇣ Data Flow
hashlib.sha1(s).hexdigest()[:16])
✓ Fix Analysis
Details
Sensitive information should never be stored in plain text, since this makes it very easy for unauthorized users, whether malicious insiders or outside attackers, to access. Hashing methods are used to make stored passwords and other sensitive data unreadable to users. For example, when a password is defined for the first time, it is hashed and then stored. The next time that user attempts to log on, the password they enter is hashed following the same procedure and compared with the stored value. In this way, the original password never needs to be stored in the system.
Hashing is a one-way scheme, meaning a hashed password cannot be reverse engineered. However, if an outdated or custom programmed hashing scheme is used, it becomes simple for an attacker with powerful modern computing power to gain access to the hashes used. This opens up access to all stored password information, leading to breached security. Therefore, it is essential for developers to understand modern, secure password hashing techniques.
Best practices for prevention
- Use strong standard algorithms for hashing rather than simpler but outdated methods or DIY hashing schemes, which may have inherent weaknesses.
- Use modular design for all code dealing with hashing so it can be swapped out as security standards change over time.
- Use salting in combination with hashing (While this places more demands on resources, it is an essential step for tighter security.).
- Implement zero-trust architecture to ensure that access to password data is granted only for legitimate business purposes.
- Increase developer awareness of current standards in data security and cryptography.
Use of Password Hash With Insufficient Computational Effort
hashlib.sha1 is insecure. Consider changing it to a secure hashing algorithm.
⇣ Data Flow
sha1(name.encode("utf-8"))
✓ Fix Analysis
Details
Sensitive information should never be stored in plain text, since this makes it very easy for unauthorized users, whether malicious insiders or outside attackers, to access. Hashing methods are used to make stored passwords and other sensitive data unreadable to users. For example, when a password is defined for the first time, it is hashed and then stored. The next time that user attempts to log on, the password they enter is hashed following the same procedure and compared with the stored value. In this way, the original password never needs to be stored in the system.
Hashing is a one-way scheme, meaning a hashed password cannot be reverse engineered. However, if an outdated or custom programmed hashing scheme is used, it becomes simple for an attacker with powerful modern computing power to gain access to the hashes used. This opens up access to all stored password information, leading to breached security. Therefore, it is essential for developers to understand modern, secure password hashing techniques.
Best practices for prevention
- Use strong standard algorithms for hashing rather than simpler but outdated methods or DIY hashing schemes, which may have inherent weaknesses.
- Use modular design for all code dealing with hashing so it can be swapped out as security standards change over time.
- Use salting in combination with hashing (While this places more demands on resources, it is an essential step for tighter security.).
- Implement zero-trust architecture to ensure that access to password data is granted only for legitimate business purposes.
- Increase developer awareness of current standards in data security and cryptography.
Use of Password Hash With Insufficient Computational Effort
hashlib.sha1 is insecure. Consider changing it to a secure hashing algorithm.
⇣ Data Flow
sha1(source.encode("utf-8")).hexdigest()
✓ Fix Analysis
Details
Sensitive information should never be stored in plain text, since this makes it very easy for unauthorized users, whether malicious insiders or outside attackers, to access. Hashing methods are used to make stored passwords and other sensitive data unreadable to users. For example, when a password is defined for the first time, it is hashed and then stored. The next time that user attempts to log on, the password they enter is hashed following the same procedure and compared with the stored value. In this way, the original password never needs to be stored in the system.
Hashing is a one-way scheme, meaning a hashed password cannot be reverse engineered. However, if an outdated or custom programmed hashing scheme is used, it becomes simple for an attacker with powerful modern computing power to gain access to the hashes used. This opens up access to all stored password information, leading to breached security. Therefore, it is essential for developers to understand modern, secure password hashing techniques.
Best practices for prevention
- Use strong standard algorithms for hashing rather than simpler but outdated methods or DIY hashing schemes, which may have inherent weaknesses.
- Use modular design for all code dealing with hashing so it can be swapped out as security standards change over time.
- Use salting in combination with hashing (While this places more demands on resources, it is an essential step for tighter security.).
- Implement zero-trust architecture to ensure that access to password data is granted only for legitimate business purposes.
- Increase developer awareness of current standards in data security and cryptography.
Use of Password Hash With Insufficient Computational Effort
hashlib.md5 is insecure. Consider changing it to a secure hashing algorithm.
⇣ Data Flow
hashlib.md5(x).hexdigest()
✓ Fix Analysis
Details
Sensitive information should never be stored in plain text, since this makes it very easy for unauthorized users, whether malicious insiders or outside attackers, to access. Hashing methods are used to make stored passwords and other sensitive data unreadable to users. For example, when a password is defined for the first time, it is hashed and then stored. The next time that user attempts to log on, the password they enter is hashed following the same procedure and compared with the stored value. In this way, the original password never needs to be stored in the system.
Hashing is a one-way scheme, meaning a hashed password cannot be reverse engineered. However, if an outdated or custom programmed hashing scheme is used, it becomes simple for an attacker with powerful modern computing power to gain access to the hashes used. This opens up access to all stored password information, leading to breached security. Therefore, it is essential for developers to understand modern, secure password hashing techniques.
Best practices for prevention
- Use strong standard algorithms for hashing rather than simpler but outdated methods or DIY hashing schemes, which may have inherent weaknesses.
- Use modular design for all code dealing with hashing so it can be swapped out as security standards change over time.
- Use salting in combination with hashing (While this places more demands on resources, it is an essential step for tighter security.).
- Implement zero-trust architecture to ensure that access to password data is granted only for legitimate business purposes.
- Increase developer awareness of current standards in data security and cryptography.
Use of Hardcoded Credentials
Do not hardcode credentials in code. Found hardcoded credential used in user.
⇣ Data Flow
"user1"
user = "user1"
✓ Fix Analysis
Details
Developers may use hardcoded credentials for convenience when coding in order to simplify their workflow. While they are responsible for removing these before production, occasionally this task may fall through the cracks. This also becomes a maintenance challenge when credentials are re-used across multiple applications.
Once attackers gain access, they may take advantage of privilege level to remove or alter data, take down a site or app, or hold any of the above for ransom. The risk across multiple similar projects is even greater. If code containing the credentials is reused across multiple projects, they will all be compromised.
Best practices for prevention
- Plan software architecture such that keys and passwords are always stored outside the code, wherever possible.
- Plan encryption into software architecture for all credential information and ensure proper handling of keys, credentials, and passwords.
- Prompt for a secure password on first login rather than hard-code a default password.
- If a hardcoded password or credential must be used, limit its use, for example, to system console users rather than via the network.
- Use strong hashes for inbound password authentication, ideally with randomly assigned salts to increase the difficulty level in case of brute-force attack.
Use of Hardcoded Credentials
Do not hardcode credentials in code. Found hardcoded credential used in user.
⇣ Data Flow
"user1"
user = "user1"
✓ Fix Analysis
Details
Developers may use hardcoded credentials for convenience when coding in order to simplify their workflow. While they are responsible for removing these before production, occasionally this task may fall through the cracks. This also becomes a maintenance challenge when credentials are re-used across multiple applications.
Once attackers gain access, they may take advantage of privilege level to remove or alter data, take down a site or app, or hold any of the above for ransom. The risk across multiple similar projects is even greater. If code containing the credentials is reused across multiple projects, they will all be compromised.
Best practices for prevention
- Plan software architecture such that keys and passwords are always stored outside the code, wherever possible.
- Plan encryption into software architecture for all credential information and ensure proper handling of keys, credentials, and passwords.
- Prompt for a secure password on first login rather than hard-code a default password.
- If a hardcoded password or credential must be used, limit its use, for example, to system console users rather than via the network.
- Use strong hashes for inbound password authentication, ideally with randomly assigned salts to increase the difficulty level in case of brute-force attack.
Use of Hardcoded Credentials
Do not hardcode credentials in code. Found hardcoded credential used in user.
⇣ Data Flow
"user2"
user = "user2"
✓ Fix Analysis
Details
Developers may use hardcoded credentials for convenience when coding in order to simplify their workflow. While they are responsible for removing these before production, occasionally this task may fall through the cracks. This also becomes a maintenance challenge when credentials are re-used across multiple applications.
Once attackers gain access, they may take advantage of privilege level to remove or alter data, take down a site or app, or hold any of the above for ransom. The risk across multiple similar projects is even greater. If code containing the credentials is reused across multiple projects, they will all be compromised.
Best practices for prevention
- Plan software architecture such that keys and passwords are always stored outside the code, wherever possible.
- Plan encryption into software architecture for all credential information and ensure proper handling of keys, credentials, and passwords.
- Prompt for a secure password on first login rather than hard-code a default password.
- If a hardcoded password or credential must be used, limit its use, for example, to system console users rather than via the network.
- Use strong hashes for inbound password authentication, ideally with randomly assigned salts to increase the difficulty level in case of brute-force attack.
Use of Hardcoded Credentials
Do not hardcode credentials in code. Found hardcoded credential used in username.
⇣ Data Flow
"valid_user"
username = "valid_user"
✓ Fix Analysis
Details
Developers may use hardcoded credentials for convenience when coding in order to simplify their workflow. While they are responsible for removing these before production, occasionally this task may fall through the cracks. This also becomes a maintenance challenge when credentials are re-used across multiple applications.
Once attackers gain access, they may take advantage of privilege level to remove or alter data, take down a site or app, or hold any of the above for ransom. The risk across multiple similar projects is even greater. If code containing the credentials is reused across multiple projects, they will all be compromised.
Best practices for prevention
- Plan software architecture such that keys and passwords are always stored outside the code, wherever possible.
- Plan encryption into software architecture for all credential information and ensure proper handling of keys, credentials, and passwords.
- Prompt for a secure password on first login rather than hard-code a default password.
- If a hardcoded password or credential must be used, limit its use, for example, to system console users rather than via the network.
- Use strong hashes for inbound password authentication, ideally with randomly assigned salts to increase the difficulty level in case of brute-force attack.
Use of Hardcoded Credentials
Do not hardcode credentials in code. Found hardcoded credential used in username.
⇣ Data Flow
"invalid_user"
username = "invalid_user"
✓ Fix Analysis
Details
Developers may use hardcoded credentials for convenience when coding in order to simplify their workflow. While they are responsible for removing these before production, occasionally this task may fall through the cracks. This also becomes a maintenance challenge when credentials are re-used across multiple applications.
Once attackers gain access, they may take advantage of privilege level to remove or alter data, take down a site or app, or hold any of the above for ransom. The risk across multiple similar projects is even greater. If code containing the credentials is reused across multiple projects, they will all be compromised.
Best practices for prevention
- Plan software architecture such that keys and passwords are always stored outside the code, wherever possible.
- Plan encryption into software architecture for all credential information and ensure proper handling of keys, credentials, and passwords.
- Prompt for a secure password on first login rather than hard-code a default password.
- If a hardcoded password or credential must be used, limit its use, for example, to system console users rather than via the network.
- Use strong hashes for inbound password authentication, ideally with randomly assigned salts to increase the difficulty level in case of brute-force attack.
Use of Hardcoded Credentials
Do not hardcode credentials in code. Found hardcoded credential used in username.
⇣ Data Flow
"existing_user"
username = "existing_user"
✓ Fix Analysis
Details
Developers may use hardcoded credentials for convenience when coding in order to simplify their workflow. While they are responsible for removing these before production, occasionally this task may fall through the cracks. This also becomes a maintenance challenge when credentials are re-used across multiple applications.
Once attackers gain access, they may take advantage of privilege level to remove or alter data, take down a site or app, or hold any of the above for ransom. The risk across multiple similar projects is even greater. If code containing the credentials is reused across multiple projects, they will all be compromised.
Best practices for prevention
- Plan software architecture such that keys and passwords are always stored outside the code, wherever possible.
- Plan encryption into software architecture for all credential information and ensure proper handling of keys, credentials, and passwords.
- Prompt for a secure password on first login rather than hard-code a default password.
- If a hardcoded password or credential must be used, limit its use, for example, to system console users rather than via the network.
- Use strong hashes for inbound password authentication, ideally with randomly assigned salts to increase the difficulty level in case of brute-force attack.
Cross-site Scripting (XSS)
Unsanitized input from the document location flows into a 'src' script element attribute, where it is used to dynamically construct the HTML page on client side. This may result in a DOM Based Cross-Site Scripting attack (DOMXSS).
⇣ Data Flow
href;
href;
url = window.location.href;
url.indexOf('?');
url.substr(startOfQueryString) : '';
substr(startOfQueryString) : '';
queryString = startOfQueryString > -1 ? url.substr(startOfQueryString) : '';
queryString;
'class.js' + queryString;
✓ Fix Analysis
Details
A cross-site scripting attack occurs when the attacker tricks a legitimate web-based application or site to accept a request as originating from a trusted source.
This is done by escaping the context of the web application; the web application then delivers that data to its users along with other trusted dynamic content, without validating it. The browser unknowingly executes malicious script on the client side (through client-side languages; usually JavaScript or HTML) in order to perform actions that are otherwise typically blocked by the browser's Same Origin Policy.
Injecting malicious code is the most prevalent manner by which XSS is exploited; for this reason, escaping characters in order to prevent this manipulation is the top method for securing code against this vulnerability.
Escaping means that the application is coded to mark key characters, and particularly key characters included in user input, to prevent those characters from being interpreted in a dangerous context. For example, in HTML, < can be coded as < and > can be coded as > in order to be interpreted and displayed as themselves in text, while within the code itself, they are used for HTML tags. If malicious content is injected into an application that escapes special characters and that malicious content uses < and > as HTML tags, those characters are nonetheless not interpreted as HTML tags by the browser if they've been correctly escaped in the application code and in this way the attempted attack is diverted.
The most prominent use of XSS is to steal cookies (source: OWASP HttpOnly) and hijack user sessions, but XSS exploits have been used to expose sensitive information, enable access to privileged services and functionality and deliver malware.
Types of attacks
There are a few methods by which XSS can be manipulated:
| Type | Origin | Description |
|---|---|---|
| Stored | Server | The malicious code is inserted in the application (usually as a link) by the attacker. The code is activated every time a user clicks the link. |
| Reflected | Server | The attacker delivers a malicious link externally from the vulnerable web site application to a user. When clicked, malicious code is sent to the vulnerable web site, which reflects the attack back to the user's browser. |
| DOM-based | Client | The attacker forces the user's browser to render a malicious page. The data in the page itself delivers the cross-site scripting data. |
| Mutated | The attacker injects code that appears safe, but is then rewritten and modified by the browser, while parsing the markup. An example is rebalancing unclosed quotation marks or even adding quotation marks to unquoted parameters. |
Affected environments
The following environments are susceptible to an XSS attack:
- Web servers
- Application servers
- Web application environments
Best practices for prevention
This section describes the top best practices designed to specifically protect your code:
- Sanitize data input in an HTTP request before reflecting it back, ensuring all data is validated, filtered or escaped before echoing anything back to the user, such as the values of query parameters during searches.
- Convert special characters such as
?,&,/,<,>and spaces to their respective HTML or URL encoded equivalents. - Give users the option to disable client-side scripts.
- Redirect invalid requests.
- Detect simultaneous logins, including those from two separate IP addresses, and invalidate those sessions.
- Use and enforce a Content Security Policy (source: Wikipedia) to disable any features that might be manipulated for an XSS attack.
- Read the documentation for any of the libraries referenced in your code to understand which elements allow for embedded HTML.
Cross-site Scripting (XSS)
Unsanitized input from the document location flows into a 'src' script element attribute, where it is used to dynamically construct the HTML page on client side. This may result in a DOM Based Cross-Site Scripting attack (DOMXSS).
⇣ Data Flow
href;
href;
url = window.location.href;
url.indexOf('?');
url.substr(startOfQueryString) : '';
substr(startOfQueryString) : '';
queryString = startOfQueryString > -1 ? url.substr(startOfQueryString) : '';
queryString;
'class.js' + queryString;
✓ Fix Analysis
Details
A cross-site scripting attack occurs when the attacker tricks a legitimate web-based application or site to accept a request as originating from a trusted source.
This is done by escaping the context of the web application; the web application then delivers that data to its users along with other trusted dynamic content, without validating it. The browser unknowingly executes malicious script on the client side (through client-side languages; usually JavaScript or HTML) in order to perform actions that are otherwise typically blocked by the browser's Same Origin Policy.
Injecting malicious code is the most prevalent manner by which XSS is exploited; for this reason, escaping characters in order to prevent this manipulation is the top method for securing code against this vulnerability.
Escaping means that the application is coded to mark key characters, and particularly key characters included in user input, to prevent those characters from being interpreted in a dangerous context. For example, in HTML, < can be coded as < and > can be coded as > in order to be interpreted and displayed as themselves in text, while within the code itself, they are used for HTML tags. If malicious content is injected into an application that escapes special characters and that malicious content uses < and > as HTML tags, those characters are nonetheless not interpreted as HTML tags by the browser if they've been correctly escaped in the application code and in this way the attempted attack is diverted.
The most prominent use of XSS is to steal cookies (source: OWASP HttpOnly) and hijack user sessions, but XSS exploits have been used to expose sensitive information, enable access to privileged services and functionality and deliver malware.
Types of attacks
There are a few methods by which XSS can be manipulated:
| Type | Origin | Description |
|---|---|---|
| Stored | Server | The malicious code is inserted in the application (usually as a link) by the attacker. The code is activated every time a user clicks the link. |
| Reflected | Server | The attacker delivers a malicious link externally from the vulnerable web site application to a user. When clicked, malicious code is sent to the vulnerable web site, which reflects the attack back to the user's browser. |
| DOM-based | Client | The attacker forces the user's browser to render a malicious page. The data in the page itself delivers the cross-site scripting data. |
| Mutated | The attacker injects code that appears safe, but is then rewritten and modified by the browser, while parsing the markup. An example is rebalancing unclosed quotation marks or even adding quotation marks to unquoted parameters. |
Affected environments
The following environments are susceptible to an XSS attack:
- Web servers
- Application servers
- Web application environments
Best practices for prevention
This section describes the top best practices designed to specifically protect your code:
- Sanitize data input in an HTTP request before reflecting it back, ensuring all data is validated, filtered or escaped before echoing anything back to the user, such as the values of query parameters during searches.
- Convert special characters such as
?,&,/,<,>and spaces to their respective HTML or URL encoded equivalents. - Give users the option to disable client-side scripts.
- Redirect invalid requests.
- Detect simultaneous logins, including those from two separate IP addresses, and invalidate those sessions.
- Use and enforce a Content Security Policy (source: Wikipedia) to disable any features that might be manipulated for an XSS attack.
- Read the documentation for any of the libraries referenced in your code to understand which elements allow for embedded HTML.
Cross-site Scripting (XSS)
Unsanitized input from the document location flows into a 'src' script element attribute, where it is used to dynamically construct the HTML page on client side. This may result in a DOM Based Cross-Site Scripting attack (DOMXSS).
⇣ Data Flow
href;
href;
url = window.location.href;
url.indexOf('?');
url.substr(startOfQueryString) : '';
substr(startOfQueryString) : '';
queryString = startOfQueryString > -1 ? url.substr(startOfQueryString) : '';
queryString;
'class.js' + queryString;
✓ Fix Analysis
Details
A cross-site scripting attack occurs when the attacker tricks a legitimate web-based application or site to accept a request as originating from a trusted source.
This is done by escaping the context of the web application; the web application then delivers that data to its users along with other trusted dynamic content, without validating it. The browser unknowingly executes malicious script on the client side (through client-side languages; usually JavaScript or HTML) in order to perform actions that are otherwise typically blocked by the browser's Same Origin Policy.
Injecting malicious code is the most prevalent manner by which XSS is exploited; for this reason, escaping characters in order to prevent this manipulation is the top method for securing code against this vulnerability.
Escaping means that the application is coded to mark key characters, and particularly key characters included in user input, to prevent those characters from being interpreted in a dangerous context. For example, in HTML, < can be coded as < and > can be coded as > in order to be interpreted and displayed as themselves in text, while within the code itself, they are used for HTML tags. If malicious content is injected into an application that escapes special characters and that malicious content uses < and > as HTML tags, those characters are nonetheless not interpreted as HTML tags by the browser if they've been correctly escaped in the application code and in this way the attempted attack is diverted.
The most prominent use of XSS is to steal cookies (source: OWASP HttpOnly) and hijack user sessions, but XSS exploits have been used to expose sensitive information, enable access to privileged services and functionality and deliver malware.
Types of attacks
There are a few methods by which XSS can be manipulated:
| Type | Origin | Description |
|---|---|---|
| Stored | Server | The malicious code is inserted in the application (usually as a link) by the attacker. The code is activated every time a user clicks the link. |
| Reflected | Server | The attacker delivers a malicious link externally from the vulnerable web site application to a user. When clicked, malicious code is sent to the vulnerable web site, which reflects the attack back to the user's browser. |
| DOM-based | Client | The attacker forces the user's browser to render a malicious page. The data in the page itself delivers the cross-site scripting data. |
| Mutated | The attacker injects code that appears safe, but is then rewritten and modified by the browser, while parsing the markup. An example is rebalancing unclosed quotation marks or even adding quotation marks to unquoted parameters. |
Affected environments
The following environments are susceptible to an XSS attack:
- Web servers
- Application servers
- Web application environments
Best practices for prevention
This section describes the top best practices designed to specifically protect your code:
- Sanitize data input in an HTTP request before reflecting it back, ensuring all data is validated, filtered or escaped before echoing anything back to the user, such as the values of query parameters during searches.
- Convert special characters such as
?,&,/,<,>and spaces to their respective HTML or URL encoded equivalents. - Give users the option to disable client-side scripts.
- Redirect invalid requests.
- Detect simultaneous logins, including those from two separate IP addresses, and invalidate those sessions.
- Use and enforce a Content Security Policy (source: Wikipedia) to disable any features that might be manipulated for an XSS attack.
- Read the documentation for any of the libraries referenced in your code to understand which elements allow for embedded HTML.
Cross-site Scripting (XSS)
Unsanitized input from the document location flows into a 'src' script element attribute, where it is used to dynamically construct the HTML page on client side. This may result in a DOM Based Cross-Site Scripting attack (DOMXSS).
⇣ Data Flow
href;
href;
url = window.location.href;
url.indexOf('?');
url.substr(startOfQueryString) : '';
substr(startOfQueryString) : '';
queryString = startOfQueryString > -1 ? url.substr(startOfQueryString) : '';
queryString;
'class.js' + queryString;
✓ Fix Analysis
Details
A cross-site scripting attack occurs when the attacker tricks a legitimate web-based application or site to accept a request as originating from a trusted source.
This is done by escaping the context of the web application; the web application then delivers that data to its users along with other trusted dynamic content, without validating it. The browser unknowingly executes malicious script on the client side (through client-side languages; usually JavaScript or HTML) in order to perform actions that are otherwise typically blocked by the browser's Same Origin Policy.
Injecting malicious code is the most prevalent manner by which XSS is exploited; for this reason, escaping characters in order to prevent this manipulation is the top method for securing code against this vulnerability.
Escaping means that the application is coded to mark key characters, and particularly key characters included in user input, to prevent those characters from being interpreted in a dangerous context. For example, in HTML, < can be coded as < and > can be coded as > in order to be interpreted and displayed as themselves in text, while within the code itself, they are used for HTML tags. If malicious content is injected into an application that escapes special characters and that malicious content uses < and > as HTML tags, those characters are nonetheless not interpreted as HTML tags by the browser if they've been correctly escaped in the application code and in this way the attempted attack is diverted.
The most prominent use of XSS is to steal cookies (source: OWASP HttpOnly) and hijack user sessions, but XSS exploits have been used to expose sensitive information, enable access to privileged services and functionality and deliver malware.
Types of attacks
There are a few methods by which XSS can be manipulated:
| Type | Origin | Description |
|---|---|---|
| Stored | Server | The malicious code is inserted in the application (usually as a link) by the attacker. The code is activated every time a user clicks the link. |
| Reflected | Server | The attacker delivers a malicious link externally from the vulnerable web site application to a user. When clicked, malicious code is sent to the vulnerable web site, which reflects the attack back to the user's browser. |
| DOM-based | Client | The attacker forces the user's browser to render a malicious page. The data in the page itself delivers the cross-site scripting data. |
| Mutated | The attacker injects code that appears safe, but is then rewritten and modified by the browser, while parsing the markup. An example is rebalancing unclosed quotation marks or even adding quotation marks to unquoted parameters. |
Affected environments
The following environments are susceptible to an XSS attack:
- Web servers
- Application servers
- Web application environments
Best practices for prevention
This section describes the top best practices designed to specifically protect your code:
- Sanitize data input in an HTTP request before reflecting it back, ensuring all data is validated, filtered or escaped before echoing anything back to the user, such as the values of query parameters during searches.
- Convert special characters such as
?,&,/,<,>and spaces to their respective HTML or URL encoded equivalents. - Give users the option to disable client-side scripts.
- Redirect invalid requests.
- Detect simultaneous logins, including those from two separate IP addresses, and invalidate those sessions.
- Use and enforce a Content Security Policy (source: Wikipedia) to disable any features that might be manipulated for an XSS attack.
- Read the documentation for any of the libraries referenced in your code to understand which elements allow for embedded HTML.
Cross-site Scripting (XSS)
Unsanitized input from the document location flows into a 'src' script element attribute, where it is used to dynamically construct the HTML page on client side. This may result in a DOM Based Cross-Site Scripting attack (DOMXSS).
⇣ Data Flow
href;
href;
url = window.location.href;
url.indexOf('?');
url.substr(startOfQueryString) : '';
substr(startOfQueryString) : '';
queryString = startOfQueryString > -1 ? url.substr(startOfQueryString) : '';
queryString;
'main.js' + queryString;
✓ Fix Analysis
Details
A cross-site scripting attack occurs when the attacker tricks a legitimate web-based application or site to accept a request as originating from a trusted source.
This is done by escaping the context of the web application; the web application then delivers that data to its users along with other trusted dynamic content, without validating it. The browser unknowingly executes malicious script on the client side (through client-side languages; usually JavaScript or HTML) in order to perform actions that are otherwise typically blocked by the browser's Same Origin Policy.
Injecting malicious code is the most prevalent manner by which XSS is exploited; for this reason, escaping characters in order to prevent this manipulation is the top method for securing code against this vulnerability.
Escaping means that the application is coded to mark key characters, and particularly key characters included in user input, to prevent those characters from being interpreted in a dangerous context. For example, in HTML, < can be coded as < and > can be coded as > in order to be interpreted and displayed as themselves in text, while within the code itself, they are used for HTML tags. If malicious content is injected into an application that escapes special characters and that malicious content uses < and > as HTML tags, those characters are nonetheless not interpreted as HTML tags by the browser if they've been correctly escaped in the application code and in this way the attempted attack is diverted.
The most prominent use of XSS is to steal cookies (source: OWASP HttpOnly) and hijack user sessions, but XSS exploits have been used to expose sensitive information, enable access to privileged services and functionality and deliver malware.
Types of attacks
There are a few methods by which XSS can be manipulated:
| Type | Origin | Description |
|---|---|---|
| Stored | Server | The malicious code is inserted in the application (usually as a link) by the attacker. The code is activated every time a user clicks the link. |
| Reflected | Server | The attacker delivers a malicious link externally from the vulnerable web site application to a user. When clicked, malicious code is sent to the vulnerable web site, which reflects the attack back to the user's browser. |
| DOM-based | Client | The attacker forces the user's browser to render a malicious page. The data in the page itself delivers the cross-site scripting data. |
| Mutated | The attacker injects code that appears safe, but is then rewritten and modified by the browser, while parsing the markup. An example is rebalancing unclosed quotation marks or even adding quotation marks to unquoted parameters. |
Affected environments
The following environments are susceptible to an XSS attack:
- Web servers
- Application servers
- Web application environments
Best practices for prevention
This section describes the top best practices designed to specifically protect your code:
- Sanitize data input in an HTTP request before reflecting it back, ensuring all data is validated, filtered or escaped before echoing anything back to the user, such as the values of query parameters during searches.
- Convert special characters such as
?,&,/,<,>and spaces to their respective HTML or URL encoded equivalents. - Give users the option to disable client-side scripts.
- Redirect invalid requests.
- Detect simultaneous logins, including those from two separate IP addresses, and invalidate those sessions.
- Use and enforce a Content Security Policy (source: Wikipedia) to disable any features that might be manipulated for an XSS attack.
- Read the documentation for any of the libraries referenced in your code to understand which elements allow for embedded HTML.
Cross-site Scripting (XSS)
Unsanitized input from the document location flows into a 'src' script element attribute, where it is used to dynamically construct the HTML page on client side. This may result in a DOM Based Cross-Site Scripting attack (DOMXSS).
⇣ Data Flow
href;
href;
url = window.location.href;
url.indexOf('?');
url.substr(startOfQueryString) : '';
substr(startOfQueryString) : '';
queryString = startOfQueryString > -1 ? url.substr(startOfQueryString) : '';
queryString;
'class.js' + queryString;
✓ Fix Analysis
Details
A cross-site scripting attack occurs when the attacker tricks a legitimate web-based application or site to accept a request as originating from a trusted source.
This is done by escaping the context of the web application; the web application then delivers that data to its users along with other trusted dynamic content, without validating it. The browser unknowingly executes malicious script on the client side (through client-side languages; usually JavaScript or HTML) in order to perform actions that are otherwise typically blocked by the browser's Same Origin Policy.
Injecting malicious code is the most prevalent manner by which XSS is exploited; for this reason, escaping characters in order to prevent this manipulation is the top method for securing code against this vulnerability.
Escaping means that the application is coded to mark key characters, and particularly key characters included in user input, to prevent those characters from being interpreted in a dangerous context. For example, in HTML, < can be coded as < and > can be coded as > in order to be interpreted and displayed as themselves in text, while within the code itself, they are used for HTML tags. If malicious content is injected into an application that escapes special characters and that malicious content uses < and > as HTML tags, those characters are nonetheless not interpreted as HTML tags by the browser if they've been correctly escaped in the application code and in this way the attempted attack is diverted.
The most prominent use of XSS is to steal cookies (source: OWASP HttpOnly) and hijack user sessions, but XSS exploits have been used to expose sensitive information, enable access to privileged services and functionality and deliver malware.
Types of attacks
There are a few methods by which XSS can be manipulated:
| Type | Origin | Description |
|---|---|---|
| Stored | Server | The malicious code is inserted in the application (usually as a link) by the attacker. The code is activated every time a user clicks the link. |
| Reflected | Server | The attacker delivers a malicious link externally from the vulnerable web site application to a user. When clicked, malicious code is sent to the vulnerable web site, which reflects the attack back to the user's browser. |
| DOM-based | Client | The attacker forces the user's browser to render a malicious page. The data in the page itself delivers the cross-site scripting data. |
| Mutated | The attacker injects code that appears safe, but is then rewritten and modified by the browser, while parsing the markup. An example is rebalancing unclosed quotation marks or even adding quotation marks to unquoted parameters. |
Affected environments
The following environments are susceptible to an XSS attack:
- Web servers
- Application servers
- Web application environments
Best practices for prevention
This section describes the top best practices designed to specifically protect your code:
- Sanitize data input in an HTTP request before reflecting it back, ensuring all data is validated, filtered or escaped before echoing anything back to the user, such as the values of query parameters during searches.
- Convert special characters such as
?,&,/,<,>and spaces to their respective HTML or URL encoded equivalents. - Give users the option to disable client-side scripts.
- Redirect invalid requests.
- Detect simultaneous logins, including those from two separate IP addresses, and invalidate those sessions.
- Use and enforce a Content Security Policy (source: Wikipedia) to disable any features that might be manipulated for an XSS attack.
- Read the documentation for any of the libraries referenced in your code to understand which elements allow for embedded HTML.
Cross-site Scripting (XSS)
Unsanitized input from the document location flows into a 'src' script element attribute, where it is used to dynamically construct the HTML page on client side. This may result in a DOM Based Cross-Site Scripting attack (DOMXSS).
⇣ Data Flow
href;
href;
url = window.location.href;
url.indexOf('?');
url.substr(startOfQueryString) : '';
substr(startOfQueryString) : '';
queryString = startOfQueryString > -1 ? url.substr(startOfQueryString) : '';
queryString;
'class.js' + queryString;
✓ Fix Analysis
Details
A cross-site scripting attack occurs when the attacker tricks a legitimate web-based application or site to accept a request as originating from a trusted source.
This is done by escaping the context of the web application; the web application then delivers that data to its users along with other trusted dynamic content, without validating it. The browser unknowingly executes malicious script on the client side (through client-side languages; usually JavaScript or HTML) in order to perform actions that are otherwise typically blocked by the browser's Same Origin Policy.
Injecting malicious code is the most prevalent manner by which XSS is exploited; for this reason, escaping characters in order to prevent this manipulation is the top method for securing code against this vulnerability.
Escaping means that the application is coded to mark key characters, and particularly key characters included in user input, to prevent those characters from being interpreted in a dangerous context. For example, in HTML, < can be coded as < and > can be coded as > in order to be interpreted and displayed as themselves in text, while within the code itself, they are used for HTML tags. If malicious content is injected into an application that escapes special characters and that malicious content uses < and > as HTML tags, those characters are nonetheless not interpreted as HTML tags by the browser if they've been correctly escaped in the application code and in this way the attempted attack is diverted.
The most prominent use of XSS is to steal cookies (source: OWASP HttpOnly) and hijack user sessions, but XSS exploits have been used to expose sensitive information, enable access to privileged services and functionality and deliver malware.
Types of attacks
There are a few methods by which XSS can be manipulated:
| Type | Origin | Description |
|---|---|---|
| Stored | Server | The malicious code is inserted in the application (usually as a link) by the attacker. The code is activated every time a user clicks the link. |
| Reflected | Server | The attacker delivers a malicious link externally from the vulnerable web site application to a user. When clicked, malicious code is sent to the vulnerable web site, which reflects the attack back to the user's browser. |
| DOM-based | Client | The attacker forces the user's browser to render a malicious page. The data in the page itself delivers the cross-site scripting data. |
| Mutated | The attacker injects code that appears safe, but is then rewritten and modified by the browser, while parsing the markup. An example is rebalancing unclosed quotation marks or even adding quotation marks to unquoted parameters. |
Affected environments
The following environments are susceptible to an XSS attack:
- Web servers
- Application servers
- Web application environments
Best practices for prevention
This section describes the top best practices designed to specifically protect your code:
- Sanitize data input in an HTTP request before reflecting it back, ensuring all data is validated, filtered or escaped before echoing anything back to the user, such as the values of query parameters during searches.
- Convert special characters such as
?,&,/,<,>and spaces to their respective HTML or URL encoded equivalents. - Give users the option to disable client-side scripts.
- Redirect invalid requests.
- Detect simultaneous logins, including those from two separate IP addresses, and invalidate those sessions.
- Use and enforce a Content Security Policy (source: Wikipedia) to disable any features that might be manipulated for an XSS attack.
- Read the documentation for any of the libraries referenced in your code to understand which elements allow for embedded HTML.
Cross-site Scripting (XSS)
Unsanitized input from the document location flows into a 'src' script element attribute, where it is used to dynamically construct the HTML page on client side. This may result in a DOM Based Cross-Site Scripting attack (DOMXSS).
⇣ Data Flow
href;
href;
url = window.location.href;
url.indexOf('?');
url.substr(startOfQueryString) : '';
substr(startOfQueryString) : '';
queryString = startOfQueryString > -1 ? url.substr(startOfQueryString) : '';
queryString;
'class.js' + queryString;
✓ Fix Analysis
Details
A cross-site scripting attack occurs when the attacker tricks a legitimate web-based application or site to accept a request as originating from a trusted source.
This is done by escaping the context of the web application; the web application then delivers that data to its users along with other trusted dynamic content, without validating it. The browser unknowingly executes malicious script on the client side (through client-side languages; usually JavaScript or HTML) in order to perform actions that are otherwise typically blocked by the browser's Same Origin Policy.
Injecting malicious code is the most prevalent manner by which XSS is exploited; for this reason, escaping characters in order to prevent this manipulation is the top method for securing code against this vulnerability.
Escaping means that the application is coded to mark key characters, and particularly key characters included in user input, to prevent those characters from being interpreted in a dangerous context. For example, in HTML, < can be coded as < and > can be coded as > in order to be interpreted and displayed as themselves in text, while within the code itself, they are used for HTML tags. If malicious content is injected into an application that escapes special characters and that malicious content uses < and > as HTML tags, those characters are nonetheless not interpreted as HTML tags by the browser if they've been correctly escaped in the application code and in this way the attempted attack is diverted.
The most prominent use of XSS is to steal cookies (source: OWASP HttpOnly) and hijack user sessions, but XSS exploits have been used to expose sensitive information, enable access to privileged services and functionality and deliver malware.
Types of attacks
There are a few methods by which XSS can be manipulated:
| Type | Origin | Description |
|---|---|---|
| Stored | Server | The malicious code is inserted in the application (usually as a link) by the attacker. The code is activated every time a user clicks the link. |
| Reflected | Server | The attacker delivers a malicious link externally from the vulnerable web site application to a user. When clicked, malicious code is sent to the vulnerable web site, which reflects the attack back to the user's browser. |
| DOM-based | Client | The attacker forces the user's browser to render a malicious page. The data in the page itself delivers the cross-site scripting data. |
| Mutated | The attacker injects code that appears safe, but is then rewritten and modified by the browser, while parsing the markup. An example is rebalancing unclosed quotation marks or even adding quotation marks to unquoted parameters. |
Affected environments
The following environments are susceptible to an XSS attack:
- Web servers
- Application servers
- Web application environments
Best practices for prevention
This section describes the top best practices designed to specifically protect your code:
- Sanitize data input in an HTTP request before reflecting it back, ensuring all data is validated, filtered or escaped before echoing anything back to the user, such as the values of query parameters during searches.
- Convert special characters such as
?,&,/,<,>and spaces to their respective HTML or URL encoded equivalents. - Give users the option to disable client-side scripts.
- Redirect invalid requests.
- Detect simultaneous logins, including those from two separate IP addresses, and invalidate those sessions.
- Use and enforce a Content Security Policy (source: Wikipedia) to disable any features that might be manipulated for an XSS attack.
- Read the documentation for any of the libraries referenced in your code to understand which elements allow for embedded HTML.
Cross-site Scripting (XSS)
Unsanitized input from the document location flows into a 'src' script element attribute, where it is used to dynamically construct the HTML page on client side. This may result in a DOM Based Cross-Site Scripting attack (DOMXSS).
⇣ Data Flow
href;
href;
url = window.location.href;
url.indexOf('?');
url.substr(startOfQueryString) : '';
substr(startOfQueryString) : '';
queryString = startOfQueryString > -1 ? url.substr(startOfQueryString) : '';
queryString;
'class.js' + queryString;
✓ Fix Analysis
Details
A cross-site scripting attack occurs when the attacker tricks a legitimate web-based application or site to accept a request as originating from a trusted source.
This is done by escaping the context of the web application; the web application then delivers that data to its users along with other trusted dynamic content, without validating it. The browser unknowingly executes malicious script on the client side (through client-side languages; usually JavaScript or HTML) in order to perform actions that are otherwise typically blocked by the browser's Same Origin Policy.
Injecting malicious code is the most prevalent manner by which XSS is exploited; for this reason, escaping characters in order to prevent this manipulation is the top method for securing code against this vulnerability.
Escaping means that the application is coded to mark key characters, and particularly key characters included in user input, to prevent those characters from being interpreted in a dangerous context. For example, in HTML, < can be coded as < and > can be coded as > in order to be interpreted and displayed as themselves in text, while within the code itself, they are used for HTML tags. If malicious content is injected into an application that escapes special characters and that malicious content uses < and > as HTML tags, those characters are nonetheless not interpreted as HTML tags by the browser if they've been correctly escaped in the application code and in this way the attempted attack is diverted.
The most prominent use of XSS is to steal cookies (source: OWASP HttpOnly) and hijack user sessions, but XSS exploits have been used to expose sensitive information, enable access to privileged services and functionality and deliver malware.
Types of attacks
There are a few methods by which XSS can be manipulated:
| Type | Origin | Description |
|---|---|---|
| Stored | Server | The malicious code is inserted in the application (usually as a link) by the attacker. The code is activated every time a user clicks the link. |
| Reflected | Server | The attacker delivers a malicious link externally from the vulnerable web site application to a user. When clicked, malicious code is sent to the vulnerable web site, which reflects the attack back to the user's browser. |
| DOM-based | Client | The attacker forces the user's browser to render a malicious page. The data in the page itself delivers the cross-site scripting data. |
| Mutated | The attacker injects code that appears safe, but is then rewritten and modified by the browser, while parsing the markup. An example is rebalancing unclosed quotation marks or even adding quotation marks to unquoted parameters. |
Affected environments
The following environments are susceptible to an XSS attack:
- Web servers
- Application servers
- Web application environments
Best practices for prevention
This section describes the top best practices designed to specifically protect your code:
- Sanitize data input in an HTTP request before reflecting it back, ensuring all data is validated, filtered or escaped before echoing anything back to the user, such as the values of query parameters during searches.
- Convert special characters such as
?,&,/,<,>and spaces to their respective HTML or URL encoded equivalents. - Give users the option to disable client-side scripts.
- Redirect invalid requests.
- Detect simultaneous logins, including those from two separate IP addresses, and invalidate those sessions.
- Use and enforce a Content Security Policy (source: Wikipedia) to disable any features that might be manipulated for an XSS attack.
- Read the documentation for any of the libraries referenced in your code to understand which elements allow for embedded HTML.
Cross-site Scripting (XSS)
Unsanitized input from the document location flows into a 'src' script element attribute, where it is used to dynamically construct the HTML page on client side. This may result in a DOM Based Cross-Site Scripting attack (DOMXSS).
⇣ Data Flow
href;
href;
url = window.location.href;
url.indexOf('?');
url.substr(startOfQueryString) : '';
substr(startOfQueryString) : '';
queryString = startOfQueryString > -1 ? url.substr(startOfQueryString) : '';
queryString;
'class.js' + queryString;
✓ Fix Analysis
Details
A cross-site scripting attack occurs when the attacker tricks a legitimate web-based application or site to accept a request as originating from a trusted source.
This is done by escaping the context of the web application; the web application then delivers that data to its users along with other trusted dynamic content, without validating it. The browser unknowingly executes malicious script on the client side (through client-side languages; usually JavaScript or HTML) in order to perform actions that are otherwise typically blocked by the browser's Same Origin Policy.
Injecting malicious code is the most prevalent manner by which XSS is exploited; for this reason, escaping characters in order to prevent this manipulation is the top method for securing code against this vulnerability.
Escaping means that the application is coded to mark key characters, and particularly key characters included in user input, to prevent those characters from being interpreted in a dangerous context. For example, in HTML, < can be coded as < and > can be coded as > in order to be interpreted and displayed as themselves in text, while within the code itself, they are used for HTML tags. If malicious content is injected into an application that escapes special characters and that malicious content uses < and > as HTML tags, those characters are nonetheless not interpreted as HTML tags by the browser if they've been correctly escaped in the application code and in this way the attempted attack is diverted.
The most prominent use of XSS is to steal cookies (source: OWASP HttpOnly) and hijack user sessions, but XSS exploits have been used to expose sensitive information, enable access to privileged services and functionality and deliver malware.
Types of attacks
There are a few methods by which XSS can be manipulated:
| Type | Origin | Description |
|---|---|---|
| Stored | Server | The malicious code is inserted in the application (usually as a link) by the attacker. The code is activated every time a user clicks the link. |
| Reflected | Server | The attacker delivers a malicious link externally from the vulnerable web site application to a user. When clicked, malicious code is sent to the vulnerable web site, which reflects the attack back to the user's browser. |
| DOM-based | Client | The attacker forces the user's browser to render a malicious page. The data in the page itself delivers the cross-site scripting data. |
| Mutated | The attacker injects code that appears safe, but is then rewritten and modified by the browser, while parsing the markup. An example is rebalancing unclosed quotation marks or even adding quotation marks to unquoted parameters. |
Affected environments
The following environments are susceptible to an XSS attack:
- Web servers
- Application servers
- Web application environments
Best practices for prevention
This section describes the top best practices designed to specifically protect your code:
- Sanitize data input in an HTTP request before reflecting it back, ensuring all data is validated, filtered or escaped before echoing anything back to the user, such as the values of query parameters during searches.
- Convert special characters such as
?,&,/,<,>and spaces to their respective HTML or URL encoded equivalents. - Give users the option to disable client-side scripts.
- Redirect invalid requests.
- Detect simultaneous logins, including those from two separate IP addresses, and invalidate those sessions.
- Use and enforce a Content Security Policy (source: Wikipedia) to disable any features that might be manipulated for an XSS attack.
- Read the documentation for any of the libraries referenced in your code to understand which elements allow for embedded HTML.
Cross-site Scripting (XSS)
Unsanitized input from the document location flows into a 'src' script element attribute, where it is used to dynamically construct the HTML page on client side. This may result in a DOM Based Cross-Site Scripting attack (DOMXSS).
⇣ Data Flow
href;
href;
url = window.location.href;
url.indexOf('?');
url.substr(startOfQueryString) : '';
substr(startOfQueryString) : '';
queryString = startOfQueryString > -1 ? url.substr(startOfQueryString) : '';
queryString;
'class.js' + queryString;
✓ Fix Analysis
Details
A cross-site scripting attack occurs when the attacker tricks a legitimate web-based application or site to accept a request as originating from a trusted source.
This is done by escaping the context of the web application; the web application then delivers that data to its users along with other trusted dynamic content, without validating it. The browser unknowingly executes malicious script on the client side (through client-side languages; usually JavaScript or HTML) in order to perform actions that are otherwise typically blocked by the browser's Same Origin Policy.
Injecting malicious code is the most prevalent manner by which XSS is exploited; for this reason, escaping characters in order to prevent this manipulation is the top method for securing code against this vulnerability.
Escaping means that the application is coded to mark key characters, and particularly key characters included in user input, to prevent those characters from being interpreted in a dangerous context. For example, in HTML, < can be coded as < and > can be coded as > in order to be interpreted and displayed as themselves in text, while within the code itself, they are used for HTML tags. If malicious content is injected into an application that escapes special characters and that malicious content uses < and > as HTML tags, those characters are nonetheless not interpreted as HTML tags by the browser if they've been correctly escaped in the application code and in this way the attempted attack is diverted.
The most prominent use of XSS is to steal cookies (source: OWASP HttpOnly) and hijack user sessions, but XSS exploits have been used to expose sensitive information, enable access to privileged services and functionality and deliver malware.
Types of attacks
There are a few methods by which XSS can be manipulated:
| Type | Origin | Description |
|---|---|---|
| Stored | Server | The malicious code is inserted in the application (usually as a link) by the attacker. The code is activated every time a user clicks the link. |
| Reflected | Server | The attacker delivers a malicious link externally from the vulnerable web site application to a user. When clicked, malicious code is sent to the vulnerable web site, which reflects the attack back to the user's browser. |
| DOM-based | Client | The attacker forces the user's browser to render a malicious page. The data in the page itself delivers the cross-site scripting data. |
| Mutated | The attacker injects code that appears safe, but is then rewritten and modified by the browser, while parsing the markup. An example is rebalancing unclosed quotation marks or even adding quotation marks to unquoted parameters. |
Affected environments
The following environments are susceptible to an XSS attack:
- Web servers
- Application servers
- Web application environments
Best practices for prevention
This section describes the top best practices designed to specifically protect your code:
- Sanitize data input in an HTTP request before reflecting it back, ensuring all data is validated, filtered or escaped before echoing anything back to the user, such as the values of query parameters during searches.
- Convert special characters such as
?,&,/,<,>and spaces to their respective HTML or URL encoded equivalents. - Give users the option to disable client-side scripts.
- Redirect invalid requests.
- Detect simultaneous logins, including those from two separate IP addresses, and invalidate those sessions.
- Use and enforce a Content Security Policy (source: Wikipedia) to disable any features that might be manipulated for an XSS attack.
- Read the documentation for any of the libraries referenced in your code to understand which elements allow for embedded HTML.
Cross-site Scripting (XSS)
Unsanitized input from the document location flows into a 'src' script element attribute, where it is used to dynamically construct the HTML page on client side. This may result in a DOM Based Cross-Site Scripting attack (DOMXSS).
⇣ Data Flow
href;
href;
url = window.location.href;
url.indexOf('?');
url.substr(startOfQueryString) : '';
substr(startOfQueryString) : '';
queryString = startOfQueryString > -1 ? url.substr(startOfQueryString) : '';
queryString;
'class.js' + queryString;
✓ Fix Analysis
Details
A cross-site scripting attack occurs when the attacker tricks a legitimate web-based application or site to accept a request as originating from a trusted source.
This is done by escaping the context of the web application; the web application then delivers that data to its users along with other trusted dynamic content, without validating it. The browser unknowingly executes malicious script on the client side (through client-side languages; usually JavaScript or HTML) in order to perform actions that are otherwise typically blocked by the browser's Same Origin Policy.
Injecting malicious code is the most prevalent manner by which XSS is exploited; for this reason, escaping characters in order to prevent this manipulation is the top method for securing code against this vulnerability.
Escaping means that the application is coded to mark key characters, and particularly key characters included in user input, to prevent those characters from being interpreted in a dangerous context. For example, in HTML, < can be coded as < and > can be coded as > in order to be interpreted and displayed as themselves in text, while within the code itself, they are used for HTML tags. If malicious content is injected into an application that escapes special characters and that malicious content uses < and > as HTML tags, those characters are nonetheless not interpreted as HTML tags by the browser if they've been correctly escaped in the application code and in this way the attempted attack is diverted.
The most prominent use of XSS is to steal cookies (source: OWASP HttpOnly) and hijack user sessions, but XSS exploits have been used to expose sensitive information, enable access to privileged services and functionality and deliver malware.
Types of attacks
There are a few methods by which XSS can be manipulated:
| Type | Origin | Description |
|---|---|---|
| Stored | Server | The malicious code is inserted in the application (usually as a link) by the attacker. The code is activated every time a user clicks the link. |
| Reflected | Server | The attacker delivers a malicious link externally from the vulnerable web site application to a user. When clicked, malicious code is sent to the vulnerable web site, which reflects the attack back to the user's browser. |
| DOM-based | Client | The attacker forces the user's browser to render a malicious page. The data in the page itself delivers the cross-site scripting data. |
| Mutated | The attacker injects code that appears safe, but is then rewritten and modified by the browser, while parsing the markup. An example is rebalancing unclosed quotation marks or even adding quotation marks to unquoted parameters. |
Affected environments
The following environments are susceptible to an XSS attack:
- Web servers
- Application servers
- Web application environments
Best practices for prevention
This section describes the top best practices designed to specifically protect your code:
- Sanitize data input in an HTTP request before reflecting it back, ensuring all data is validated, filtered or escaped before echoing anything back to the user, such as the values of query parameters during searches.
- Convert special characters such as
?,&,/,<,>and spaces to their respective HTML or URL encoded equivalents. - Give users the option to disable client-side scripts.
- Redirect invalid requests.
- Detect simultaneous logins, including those from two separate IP addresses, and invalidate those sessions.
- Use and enforce a Content Security Policy (source: Wikipedia) to disable any features that might be manipulated for an XSS attack.
- Read the documentation for any of the libraries referenced in your code to understand which elements allow for embedded HTML.
Cross-site Scripting (XSS)
Unsanitized input from the document location flows into a 'src' script element attribute, where it is used to dynamically construct the HTML page on client side. This may result in a DOM Based Cross-Site Scripting attack (DOMXSS).
⇣ Data Flow
href;
href;
url = window.location.href;
url.indexOf('?');
url.substr(startOfQueryString) : '';
substr(startOfQueryString) : '';
queryString = startOfQueryString > -1 ? url.substr(startOfQueryString) : '';
queryString;
'class.js' + queryString;
✓ Fix Analysis
Details
A cross-site scripting attack occurs when the attacker tricks a legitimate web-based application or site to accept a request as originating from a trusted source.
This is done by escaping the context of the web application; the web application then delivers that data to its users along with other trusted dynamic content, without validating it. The browser unknowingly executes malicious script on the client side (through client-side languages; usually JavaScript or HTML) in order to perform actions that are otherwise typically blocked by the browser's Same Origin Policy.
Injecting malicious code is the most prevalent manner by which XSS is exploited; for this reason, escaping characters in order to prevent this manipulation is the top method for securing code against this vulnerability.
Escaping means that the application is coded to mark key characters, and particularly key characters included in user input, to prevent those characters from being interpreted in a dangerous context. For example, in HTML, < can be coded as < and > can be coded as > in order to be interpreted and displayed as themselves in text, while within the code itself, they are used for HTML tags. If malicious content is injected into an application that escapes special characters and that malicious content uses < and > as HTML tags, those characters are nonetheless not interpreted as HTML tags by the browser if they've been correctly escaped in the application code and in this way the attempted attack is diverted.
The most prominent use of XSS is to steal cookies (source: OWASP HttpOnly) and hijack user sessions, but XSS exploits have been used to expose sensitive information, enable access to privileged services and functionality and deliver malware.
Types of attacks
There are a few methods by which XSS can be manipulated:
| Type | Origin | Description |
|---|---|---|
| Stored | Server | The malicious code is inserted in the application (usually as a link) by the attacker. The code is activated every time a user clicks the link. |
| Reflected | Server | The attacker delivers a malicious link externally from the vulnerable web site application to a user. When clicked, malicious code is sent to the vulnerable web site, which reflects the attack back to the user's browser. |
| DOM-based | Client | The attacker forces the user's browser to render a malicious page. The data in the page itself delivers the cross-site scripting data. |
| Mutated | The attacker injects code that appears safe, but is then rewritten and modified by the browser, while parsing the markup. An example is rebalancing unclosed quotation marks or even adding quotation marks to unquoted parameters. |
Affected environments
The following environments are susceptible to an XSS attack:
- Web servers
- Application servers
- Web application environments
Best practices for prevention
This section describes the top best practices designed to specifically protect your code:
- Sanitize data input in an HTTP request before reflecting it back, ensuring all data is validated, filtered or escaped before echoing anything back to the user, such as the values of query parameters during searches.
- Convert special characters such as
?,&,/,<,>and spaces to their respective HTML or URL encoded equivalents. - Give users the option to disable client-side scripts.
- Redirect invalid requests.
- Detect simultaneous logins, including those from two separate IP addresses, and invalidate those sessions.
- Use and enforce a Content Security Policy (source: Wikipedia) to disable any features that might be manipulated for an XSS attack.
- Read the documentation for any of the libraries referenced in your code to understand which elements allow for embedded HTML.
Cross-site Scripting (XSS)
Unsanitized input from the document location flows into a 'src' script element attribute, where it is used to dynamically construct the HTML page on client side. This may result in a DOM Based Cross-Site Scripting attack (DOMXSS).
⇣ Data Flow
href;
href;
url = window.location.href;
url.indexOf('?');
url.substr(startOfQueryString) : '';
substr(startOfQueryString) : '';
queryString = startOfQueryString > -1 ? url.substr(startOfQueryString) : '';
queryString;
'class.js' + queryString;
✓ Fix Analysis
Details
A cross-site scripting attack occurs when the attacker tricks a legitimate web-based application or site to accept a request as originating from a trusted source.
This is done by escaping the context of the web application; the web application then delivers that data to its users along with other trusted dynamic content, without validating it. The browser unknowingly executes malicious script on the client side (through client-side languages; usually JavaScript or HTML) in order to perform actions that are otherwise typically blocked by the browser's Same Origin Policy.
Injecting malicious code is the most prevalent manner by which XSS is exploited; for this reason, escaping characters in order to prevent this manipulation is the top method for securing code against this vulnerability.
Escaping means that the application is coded to mark key characters, and particularly key characters included in user input, to prevent those characters from being interpreted in a dangerous context. For example, in HTML, < can be coded as < and > can be coded as > in order to be interpreted and displayed as themselves in text, while within the code itself, they are used for HTML tags. If malicious content is injected into an application that escapes special characters and that malicious content uses < and > as HTML tags, those characters are nonetheless not interpreted as HTML tags by the browser if they've been correctly escaped in the application code and in this way the attempted attack is diverted.
The most prominent use of XSS is to steal cookies (source: OWASP HttpOnly) and hijack user sessions, but XSS exploits have been used to expose sensitive information, enable access to privileged services and functionality and deliver malware.
Types of attacks
There are a few methods by which XSS can be manipulated:
| Type | Origin | Description |
|---|---|---|
| Stored | Server | The malicious code is inserted in the application (usually as a link) by the attacker. The code is activated every time a user clicks the link. |
| Reflected | Server | The attacker delivers a malicious link externally from the vulnerable web site application to a user. When clicked, malicious code is sent to the vulnerable web site, which reflects the attack back to the user's browser. |
| DOM-based | Client | The attacker forces the user's browser to render a malicious page. The data in the page itself delivers the cross-site scripting data. |
| Mutated | The attacker injects code that appears safe, but is then rewritten and modified by the browser, while parsing the markup. An example is rebalancing unclosed quotation marks or even adding quotation marks to unquoted parameters. |
Affected environments
The following environments are susceptible to an XSS attack:
- Web servers
- Application servers
- Web application environments
Best practices for prevention
This section describes the top best practices designed to specifically protect your code:
- Sanitize data input in an HTTP request before reflecting it back, ensuring all data is validated, filtered or escaped before echoing anything back to the user, such as the values of query parameters during searches.
- Convert special characters such as
?,&,/,<,>and spaces to their respective HTML or URL encoded equivalents. - Give users the option to disable client-side scripts.
- Redirect invalid requests.
- Detect simultaneous logins, including those from two separate IP addresses, and invalidate those sessions.
- Use and enforce a Content Security Policy (source: Wikipedia) to disable any features that might be manipulated for an XSS attack.
- Read the documentation for any of the libraries referenced in your code to understand which elements allow for embedded HTML.
Cross-site Scripting (XSS)
Unsanitized input from the document location flows into a 'src' script element attribute, where it is used to dynamically construct the HTML page on client side. This may result in a DOM Based Cross-Site Scripting attack (DOMXSS).
⇣ Data Flow
href;
href;
url = window.location.href;
url.indexOf('?');
url.substr(startOfQueryString) : '';
substr(startOfQueryString) : '';
queryString = startOfQueryString > -1 ? url.substr(startOfQueryString) : '';
queryString;
'main.js' + queryString;
✓ Fix Analysis
Details
A cross-site scripting attack occurs when the attacker tricks a legitimate web-based application or site to accept a request as originating from a trusted source.
This is done by escaping the context of the web application; the web application then delivers that data to its users along with other trusted dynamic content, without validating it. The browser unknowingly executes malicious script on the client side (through client-side languages; usually JavaScript or HTML) in order to perform actions that are otherwise typically blocked by the browser's Same Origin Policy.
Injecting malicious code is the most prevalent manner by which XSS is exploited; for this reason, escaping characters in order to prevent this manipulation is the top method for securing code against this vulnerability.
Escaping means that the application is coded to mark key characters, and particularly key characters included in user input, to prevent those characters from being interpreted in a dangerous context. For example, in HTML, < can be coded as < and > can be coded as > in order to be interpreted and displayed as themselves in text, while within the code itself, they are used for HTML tags. If malicious content is injected into an application that escapes special characters and that malicious content uses < and > as HTML tags, those characters are nonetheless not interpreted as HTML tags by the browser if they've been correctly escaped in the application code and in this way the attempted attack is diverted.
The most prominent use of XSS is to steal cookies (source: OWASP HttpOnly) and hijack user sessions, but XSS exploits have been used to expose sensitive information, enable access to privileged services and functionality and deliver malware.
Types of attacks
There are a few methods by which XSS can be manipulated:
| Type | Origin | Description |
|---|---|---|
| Stored | Server | The malicious code is inserted in the application (usually as a link) by the attacker. The code is activated every time a user clicks the link. |
| Reflected | Server | The attacker delivers a malicious link externally from the vulnerable web site application to a user. When clicked, malicious code is sent to the vulnerable web site, which reflects the attack back to the user's browser. |
| DOM-based | Client | The attacker forces the user's browser to render a malicious page. The data in the page itself delivers the cross-site scripting data. |
| Mutated | The attacker injects code that appears safe, but is then rewritten and modified by the browser, while parsing the markup. An example is rebalancing unclosed quotation marks or even adding quotation marks to unquoted parameters. |
Affected environments
The following environments are susceptible to an XSS attack:
- Web servers
- Application servers
- Web application environments
Best practices for prevention
This section describes the top best practices designed to specifically protect your code:
- Sanitize data input in an HTTP request before reflecting it back, ensuring all data is validated, filtered or escaped before echoing anything back to the user, such as the values of query parameters during searches.
- Convert special characters such as
?,&,/,<,>and spaces to their respective HTML or URL encoded equivalents. - Give users the option to disable client-side scripts.
- Redirect invalid requests.
- Detect simultaneous logins, including those from two separate IP addresses, and invalidate those sessions.
- Use and enforce a Content Security Policy (source: Wikipedia) to disable any features that might be manipulated for an XSS attack.
- Read the documentation for any of the libraries referenced in your code to understand which elements allow for embedded HTML.
Cross-site Scripting (XSS)
Unsanitized input from the document location flows into a 'src' script element attribute, where it is used to dynamically construct the HTML page on client side. This may result in a DOM Based Cross-Site Scripting attack (DOMXSS).
⇣ Data Flow
href;
href;
url = window.location.href;
url.indexOf('?');
url.substr(startOfQueryString) : '';
substr(startOfQueryString) : '';
queryString = startOfQueryString > -1 ? url.substr(startOfQueryString) : '';
queryString;
'class.js' + queryString;
✓ Fix Analysis
Details
A cross-site scripting attack occurs when the attacker tricks a legitimate web-based application or site to accept a request as originating from a trusted source.
This is done by escaping the context of the web application; the web application then delivers that data to its users along with other trusted dynamic content, without validating it. The browser unknowingly executes malicious script on the client side (through client-side languages; usually JavaScript or HTML) in order to perform actions that are otherwise typically blocked by the browser's Same Origin Policy.
Injecting malicious code is the most prevalent manner by which XSS is exploited; for this reason, escaping characters in order to prevent this manipulation is the top method for securing code against this vulnerability.
Escaping means that the application is coded to mark key characters, and particularly key characters included in user input, to prevent those characters from being interpreted in a dangerous context. For example, in HTML, < can be coded as < and > can be coded as > in order to be interpreted and displayed as themselves in text, while within the code itself, they are used for HTML tags. If malicious content is injected into an application that escapes special characters and that malicious content uses < and > as HTML tags, those characters are nonetheless not interpreted as HTML tags by the browser if they've been correctly escaped in the application code and in this way the attempted attack is diverted.
The most prominent use of XSS is to steal cookies (source: OWASP HttpOnly) and hijack user sessions, but XSS exploits have been used to expose sensitive information, enable access to privileged services and functionality and deliver malware.
Types of attacks
There are a few methods by which XSS can be manipulated:
| Type | Origin | Description |
|---|---|---|
| Stored | Server | The malicious code is inserted in the application (usually as a link) by the attacker. The code is activated every time a user clicks the link. |
| Reflected | Server | The attacker delivers a malicious link externally from the vulnerable web site application to a user. When clicked, malicious code is sent to the vulnerable web site, which reflects the attack back to the user's browser. |
| DOM-based | Client | The attacker forces the user's browser to render a malicious page. The data in the page itself delivers the cross-site scripting data. |
| Mutated | The attacker injects code that appears safe, but is then rewritten and modified by the browser, while parsing the markup. An example is rebalancing unclosed quotation marks or even adding quotation marks to unquoted parameters. |
Affected environments
The following environments are susceptible to an XSS attack:
- Web servers
- Application servers
- Web application environments
Best practices for prevention
This section describes the top best practices designed to specifically protect your code:
- Sanitize data input in an HTTP request before reflecting it back, ensuring all data is validated, filtered or escaped before echoing anything back to the user, such as the values of query parameters during searches.
- Convert special characters such as
?,&,/,<,>and spaces to their respective HTML or URL encoded equivalents. - Give users the option to disable client-side scripts.
- Redirect invalid requests.
- Detect simultaneous logins, including those from two separate IP addresses, and invalidate those sessions.
- Use and enforce a Content Security Policy (source: Wikipedia) to disable any features that might be manipulated for an XSS attack.
- Read the documentation for any of the libraries referenced in your code to understand which elements allow for embedded HTML.
Cross-site Scripting (XSS)
Unsanitized input from the document location flows into a 'src' script element attribute, where it is used to dynamically construct the HTML page on client side. This may result in a DOM Based Cross-Site Scripting attack (DOMXSS).
⇣ Data Flow
href;
href;
url = window.location.href;
url.indexOf('?');
url.substr(startOfQueryString) : '';
substr(startOfQueryString) : '';
queryString = startOfQueryString > -1 ? url.substr(startOfQueryString) : '';
queryString;
'main.js' + queryString;
✓ Fix Analysis
Details
A cross-site scripting attack occurs when the attacker tricks a legitimate web-based application or site to accept a request as originating from a trusted source.
This is done by escaping the context of the web application; the web application then delivers that data to its users along with other trusted dynamic content, without validating it. The browser unknowingly executes malicious script on the client side (through client-side languages; usually JavaScript or HTML) in order to perform actions that are otherwise typically blocked by the browser's Same Origin Policy.
Injecting malicious code is the most prevalent manner by which XSS is exploited; for this reason, escaping characters in order to prevent this manipulation is the top method for securing code against this vulnerability.
Escaping means that the application is coded to mark key characters, and particularly key characters included in user input, to prevent those characters from being interpreted in a dangerous context. For example, in HTML, < can be coded as < and > can be coded as > in order to be interpreted and displayed as themselves in text, while within the code itself, they are used for HTML tags. If malicious content is injected into an application that escapes special characters and that malicious content uses < and > as HTML tags, those characters are nonetheless not interpreted as HTML tags by the browser if they've been correctly escaped in the application code and in this way the attempted attack is diverted.
The most prominent use of XSS is to steal cookies (source: OWASP HttpOnly) and hijack user sessions, but XSS exploits have been used to expose sensitive information, enable access to privileged services and functionality and deliver malware.
Types of attacks
There are a few methods by which XSS can be manipulated:
| Type | Origin | Description |
|---|---|---|
| Stored | Server | The malicious code is inserted in the application (usually as a link) by the attacker. The code is activated every time a user clicks the link. |
| Reflected | Server | The attacker delivers a malicious link externally from the vulnerable web site application to a user. When clicked, malicious code is sent to the vulnerable web site, which reflects the attack back to the user's browser. |
| DOM-based | Client | The attacker forces the user's browser to render a malicious page. The data in the page itself delivers the cross-site scripting data. |
| Mutated | The attacker injects code that appears safe, but is then rewritten and modified by the browser, while parsing the markup. An example is rebalancing unclosed quotation marks or even adding quotation marks to unquoted parameters. |
Affected environments
The following environments are susceptible to an XSS attack:
- Web servers
- Application servers
- Web application environments
Best practices for prevention
This section describes the top best practices designed to specifically protect your code:
- Sanitize data input in an HTTP request before reflecting it back, ensuring all data is validated, filtered or escaped before echoing anything back to the user, such as the values of query parameters during searches.
- Convert special characters such as
?,&,/,<,>and spaces to their respective HTML or URL encoded equivalents. - Give users the option to disable client-side scripts.
- Redirect invalid requests.
- Detect simultaneous logins, including those from two separate IP addresses, and invalidate those sessions.
- Use and enforce a Content Security Policy (source: Wikipedia) to disable any features that might be manipulated for an XSS attack.
- Read the documentation for any of the libraries referenced in your code to understand which elements allow for embedded HTML.
Cross-site Scripting (XSS)
Unsanitized input from the document location flows into a 'src' script element attribute, where it is used to dynamically construct the HTML page on client side. This may result in a DOM Based Cross-Site Scripting attack (DOMXSS).
⇣ Data Flow
href;
href;
url = window.location.href;
url.indexOf('?');
url.substr(startOfQueryString) : '';
substr(startOfQueryString) : '';
queryString = startOfQueryString > -1 ? url.substr(startOfQueryString) : '';
queryString;
'class.js' + queryString;
✓ Fix Analysis
Details
A cross-site scripting attack occurs when the attacker tricks a legitimate web-based application or site to accept a request as originating from a trusted source.
This is done by escaping the context of the web application; the web application then delivers that data to its users along with other trusted dynamic content, without validating it. The browser unknowingly executes malicious script on the client side (through client-side languages; usually JavaScript or HTML) in order to perform actions that are otherwise typically blocked by the browser's Same Origin Policy.
Injecting malicious code is the most prevalent manner by which XSS is exploited; for this reason, escaping characters in order to prevent this manipulation is the top method for securing code against this vulnerability.
Escaping means that the application is coded to mark key characters, and particularly key characters included in user input, to prevent those characters from being interpreted in a dangerous context. For example, in HTML, < can be coded as < and > can be coded as > in order to be interpreted and displayed as themselves in text, while within the code itself, they are used for HTML tags. If malicious content is injected into an application that escapes special characters and that malicious content uses < and > as HTML tags, those characters are nonetheless not interpreted as HTML tags by the browser if they've been correctly escaped in the application code and in this way the attempted attack is diverted.
The most prominent use of XSS is to steal cookies (source: OWASP HttpOnly) and hijack user sessions, but XSS exploits have been used to expose sensitive information, enable access to privileged services and functionality and deliver malware.
Types of attacks
There are a few methods by which XSS can be manipulated:
| Type | Origin | Description |
|---|---|---|
| Stored | Server | The malicious code is inserted in the application (usually as a link) by the attacker. The code is activated every time a user clicks the link. |
| Reflected | Server | The attacker delivers a malicious link externally from the vulnerable web site application to a user. When clicked, malicious code is sent to the vulnerable web site, which reflects the attack back to the user's browser. |
| DOM-based | Client | The attacker forces the user's browser to render a malicious page. The data in the page itself delivers the cross-site scripting data. |
| Mutated | The attacker injects code that appears safe, but is then rewritten and modified by the browser, while parsing the markup. An example is rebalancing unclosed quotation marks or even adding quotation marks to unquoted parameters. |
Affected environments
The following environments are susceptible to an XSS attack:
- Web servers
- Application servers
- Web application environments
Best practices for prevention
This section describes the top best practices designed to specifically protect your code:
- Sanitize data input in an HTTP request before reflecting it back, ensuring all data is validated, filtered or escaped before echoing anything back to the user, such as the values of query parameters during searches.
- Convert special characters such as
?,&,/,<,>and spaces to their respective HTML or URL encoded equivalents. - Give users the option to disable client-side scripts.
- Redirect invalid requests.
- Detect simultaneous logins, including those from two separate IP addresses, and invalidate those sessions.
- Use and enforce a Content Security Policy (source: Wikipedia) to disable any features that might be manipulated for an XSS attack.
- Read the documentation for any of the libraries referenced in your code to understand which elements allow for embedded HTML.
Cross-site Scripting (XSS)
Unsanitized input from the document location flows into a 'src' script element attribute, where it is used to dynamically construct the HTML page on client side. This may result in a DOM Based Cross-Site Scripting attack (DOMXSS).
⇣ Data Flow
href;
href;
url = window.location.href;
url.indexOf('?');
url.substr(startOfQueryString) : '';
substr(startOfQueryString) : '';
queryString = startOfQueryString > -1 ? url.substr(startOfQueryString) : '';
queryString;
'class.js' + queryString;
✓ Fix Analysis
Details
A cross-site scripting attack occurs when the attacker tricks a legitimate web-based application or site to accept a request as originating from a trusted source.
This is done by escaping the context of the web application; the web application then delivers that data to its users along with other trusted dynamic content, without validating it. The browser unknowingly executes malicious script on the client side (through client-side languages; usually JavaScript or HTML) in order to perform actions that are otherwise typically blocked by the browser's Same Origin Policy.
Injecting malicious code is the most prevalent manner by which XSS is exploited; for this reason, escaping characters in order to prevent this manipulation is the top method for securing code against this vulnerability.
Escaping means that the application is coded to mark key characters, and particularly key characters included in user input, to prevent those characters from being interpreted in a dangerous context. For example, in HTML, < can be coded as < and > can be coded as > in order to be interpreted and displayed as themselves in text, while within the code itself, they are used for HTML tags. If malicious content is injected into an application that escapes special characters and that malicious content uses < and > as HTML tags, those characters are nonetheless not interpreted as HTML tags by the browser if they've been correctly escaped in the application code and in this way the attempted attack is diverted.
The most prominent use of XSS is to steal cookies (source: OWASP HttpOnly) and hijack user sessions, but XSS exploits have been used to expose sensitive information, enable access to privileged services and functionality and deliver malware.
Types of attacks
There are a few methods by which XSS can be manipulated:
| Type | Origin | Description |
|---|---|---|
| Stored | Server | The malicious code is inserted in the application (usually as a link) by the attacker. The code is activated every time a user clicks the link. |
| Reflected | Server | The attacker delivers a malicious link externally from the vulnerable web site application to a user. When clicked, malicious code is sent to the vulnerable web site, which reflects the attack back to the user's browser. |
| DOM-based | Client | The attacker forces the user's browser to render a malicious page. The data in the page itself delivers the cross-site scripting data. |
| Mutated | The attacker injects code that appears safe, but is then rewritten and modified by the browser, while parsing the markup. An example is rebalancing unclosed quotation marks or even adding quotation marks to unquoted parameters. |
Affected environments
The following environments are susceptible to an XSS attack:
- Web servers
- Application servers
- Web application environments
Best practices for prevention
This section describes the top best practices designed to specifically protect your code:
- Sanitize data input in an HTTP request before reflecting it back, ensuring all data is validated, filtered or escaped before echoing anything back to the user, such as the values of query parameters during searches.
- Convert special characters such as
?,&,/,<,>and spaces to their respective HTML or URL encoded equivalents. - Give users the option to disable client-side scripts.
- Redirect invalid requests.
- Detect simultaneous logins, including those from two separate IP addresses, and invalidate those sessions.
- Use and enforce a Content Security Policy (source: Wikipedia) to disable any features that might be manipulated for an XSS attack.
- Read the documentation for any of the libraries referenced in your code to understand which elements allow for embedded HTML.
Cross-site Scripting (XSS)
Unsanitized input from the document location flows into a 'src' script element attribute, where it is used to dynamically construct the HTML page on client side. This may result in a DOM Based Cross-Site Scripting attack (DOMXSS).
⇣ Data Flow
href;
href;
url = window.location.href;
url.indexOf('?');
url.substr(startOfQueryString) : '';
substr(startOfQueryString) : '';
queryString = startOfQueryString > -1 ? url.substr(startOfQueryString) : '';
queryString;
'class.js' + queryString;
✓ Fix Analysis
Details
A cross-site scripting attack occurs when the attacker tricks a legitimate web-based application or site to accept a request as originating from a trusted source.
This is done by escaping the context of the web application; the web application then delivers that data to its users along with other trusted dynamic content, without validating it. The browser unknowingly executes malicious script on the client side (through client-side languages; usually JavaScript or HTML) in order to perform actions that are otherwise typically blocked by the browser's Same Origin Policy.
Injecting malicious code is the most prevalent manner by which XSS is exploited; for this reason, escaping characters in order to prevent this manipulation is the top method for securing code against this vulnerability.
Escaping means that the application is coded to mark key characters, and particularly key characters included in user input, to prevent those characters from being interpreted in a dangerous context. For example, in HTML, < can be coded as < and > can be coded as > in order to be interpreted and displayed as themselves in text, while within the code itself, they are used for HTML tags. If malicious content is injected into an application that escapes special characters and that malicious content uses < and > as HTML tags, those characters are nonetheless not interpreted as HTML tags by the browser if they've been correctly escaped in the application code and in this way the attempted attack is diverted.
The most prominent use of XSS is to steal cookies (source: OWASP HttpOnly) and hijack user sessions, but XSS exploits have been used to expose sensitive information, enable access to privileged services and functionality and deliver malware.
Types of attacks
There are a few methods by which XSS can be manipulated:
| Type | Origin | Description |
|---|---|---|
| Stored | Server | The malicious code is inserted in the application (usually as a link) by the attacker. The code is activated every time a user clicks the link. |
| Reflected | Server | The attacker delivers a malicious link externally from the vulnerable web site application to a user. When clicked, malicious code is sent to the vulnerable web site, which reflects the attack back to the user's browser. |
| DOM-based | Client | The attacker forces the user's browser to render a malicious page. The data in the page itself delivers the cross-site scripting data. |
| Mutated | The attacker injects code that appears safe, but is then rewritten and modified by the browser, while parsing the markup. An example is rebalancing unclosed quotation marks or even adding quotation marks to unquoted parameters. |
Affected environments
The following environments are susceptible to an XSS attack:
- Web servers
- Application servers
- Web application environments
Best practices for prevention
This section describes the top best practices designed to specifically protect your code:
- Sanitize data input in an HTTP request before reflecting it back, ensuring all data is validated, filtered or escaped before echoing anything back to the user, such as the values of query parameters during searches.
- Convert special characters such as
?,&,/,<,>and spaces to their respective HTML or URL encoded equivalents. - Give users the option to disable client-side scripts.
- Redirect invalid requests.
- Detect simultaneous logins, including those from two separate IP addresses, and invalidate those sessions.
- Use and enforce a Content Security Policy (source: Wikipedia) to disable any features that might be manipulated for an XSS attack.
- Read the documentation for any of the libraries referenced in your code to understand which elements allow for embedded HTML.
Cross-site Scripting (XSS)
Unsanitized input from the document location flows into a 'src' script element attribute, where it is used to dynamically construct the HTML page on client side. This may result in a DOM Based Cross-Site Scripting attack (DOMXSS).
⇣ Data Flow
href;
href;
url = window.location.href;
url.indexOf('?');
url.substr(startOfQueryString) : '';
substr(startOfQueryString) : '';
queryString = startOfQueryString > -1 ? url.substr(startOfQueryString) : '';
queryString;
'class.js' + queryString;
✓ Fix Analysis
Details
A cross-site scripting attack occurs when the attacker tricks a legitimate web-based application or site to accept a request as originating from a trusted source.
This is done by escaping the context of the web application; the web application then delivers that data to its users along with other trusted dynamic content, without validating it. The browser unknowingly executes malicious script on the client side (through client-side languages; usually JavaScript or HTML) in order to perform actions that are otherwise typically blocked by the browser's Same Origin Policy.
Injecting malicious code is the most prevalent manner by which XSS is exploited; for this reason, escaping characters in order to prevent this manipulation is the top method for securing code against this vulnerability.
Escaping means that the application is coded to mark key characters, and particularly key characters included in user input, to prevent those characters from being interpreted in a dangerous context. For example, in HTML, < can be coded as < and > can be coded as > in order to be interpreted and displayed as themselves in text, while within the code itself, they are used for HTML tags. If malicious content is injected into an application that escapes special characters and that malicious content uses < and > as HTML tags, those characters are nonetheless not interpreted as HTML tags by the browser if they've been correctly escaped in the application code and in this way the attempted attack is diverted.
The most prominent use of XSS is to steal cookies (source: OWASP HttpOnly) and hijack user sessions, but XSS exploits have been used to expose sensitive information, enable access to privileged services and functionality and deliver malware.
Types of attacks
There are a few methods by which XSS can be manipulated:
| Type | Origin | Description |
|---|---|---|
| Stored | Server | The malicious code is inserted in the application (usually as a link) by the attacker. The code is activated every time a user clicks the link. |
| Reflected | Server | The attacker delivers a malicious link externally from the vulnerable web site application to a user. When clicked, malicious code is sent to the vulnerable web site, which reflects the attack back to the user's browser. |
| DOM-based | Client | The attacker forces the user's browser to render a malicious page. The data in the page itself delivers the cross-site scripting data. |
| Mutated | The attacker injects code that appears safe, but is then rewritten and modified by the browser, while parsing the markup. An example is rebalancing unclosed quotation marks or even adding quotation marks to unquoted parameters. |
Affected environments
The following environments are susceptible to an XSS attack:
- Web servers
- Application servers
- Web application environments
Best practices for prevention
This section describes the top best practices designed to specifically protect your code:
- Sanitize data input in an HTTP request before reflecting it back, ensuring all data is validated, filtered or escaped before echoing anything back to the user, such as the values of query parameters during searches.
- Convert special characters such as
?,&,/,<,>and spaces to their respective HTML or URL encoded equivalents. - Give users the option to disable client-side scripts.
- Redirect invalid requests.
- Detect simultaneous logins, including those from two separate IP addresses, and invalidate those sessions.
- Use and enforce a Content Security Policy (source: Wikipedia) to disable any features that might be manipulated for an XSS attack.
- Read the documentation for any of the libraries referenced in your code to understand which elements allow for embedded HTML.
Cross-site Scripting (XSS)
Unsanitized input from the document location flows into a 'src' script element attribute, where it is used to dynamically construct the HTML page on client side. This may result in a DOM Based Cross-Site Scripting attack (DOMXSS).
⇣ Data Flow
href;
href;
url = window.location.href;
url.indexOf('?');
url.substr(startOfQueryString) : '';
substr(startOfQueryString) : '';
queryString = startOfQueryString > -1 ? url.substr(startOfQueryString) : '';
queryString;
'class.js' + queryString;
✓ Fix Analysis
Details
A cross-site scripting attack occurs when the attacker tricks a legitimate web-based application or site to accept a request as originating from a trusted source.
This is done by escaping the context of the web application; the web application then delivers that data to its users along with other trusted dynamic content, without validating it. The browser unknowingly executes malicious script on the client side (through client-side languages; usually JavaScript or HTML) in order to perform actions that are otherwise typically blocked by the browser's Same Origin Policy.
Injecting malicious code is the most prevalent manner by which XSS is exploited; for this reason, escaping characters in order to prevent this manipulation is the top method for securing code against this vulnerability.
Escaping means that the application is coded to mark key characters, and particularly key characters included in user input, to prevent those characters from being interpreted in a dangerous context. For example, in HTML, < can be coded as < and > can be coded as > in order to be interpreted and displayed as themselves in text, while within the code itself, they are used for HTML tags. If malicious content is injected into an application that escapes special characters and that malicious content uses < and > as HTML tags, those characters are nonetheless not interpreted as HTML tags by the browser if they've been correctly escaped in the application code and in this way the attempted attack is diverted.
The most prominent use of XSS is to steal cookies (source: OWASP HttpOnly) and hijack user sessions, but XSS exploits have been used to expose sensitive information, enable access to privileged services and functionality and deliver malware.
Types of attacks
There are a few methods by which XSS can be manipulated:
| Type | Origin | Description |
|---|---|---|
| Stored | Server | The malicious code is inserted in the application (usually as a link) by the attacker. The code is activated every time a user clicks the link. |
| Reflected | Server | The attacker delivers a malicious link externally from the vulnerable web site application to a user. When clicked, malicious code is sent to the vulnerable web site, which reflects the attack back to the user's browser. |
| DOM-based | Client | The attacker forces the user's browser to render a malicious page. The data in the page itself delivers the cross-site scripting data. |
| Mutated | The attacker injects code that appears safe, but is then rewritten and modified by the browser, while parsing the markup. An example is rebalancing unclosed quotation marks or even adding quotation marks to unquoted parameters. |
Affected environments
The following environments are susceptible to an XSS attack:
- Web servers
- Application servers
- Web application environments
Best practices for prevention
This section describes the top best practices designed to specifically protect your code:
- Sanitize data input in an HTTP request before reflecting it back, ensuring all data is validated, filtered or escaped before echoing anything back to the user, such as the values of query parameters during searches.
- Convert special characters such as
?,&,/,<,>and spaces to their respective HTML or URL encoded equivalents. - Give users the option to disable client-side scripts.
- Redirect invalid requests.
- Detect simultaneous logins, including those from two separate IP addresses, and invalidate those sessions.
- Use and enforce a Content Security Policy (source: Wikipedia) to disable any features that might be manipulated for an XSS attack.
- Read the documentation for any of the libraries referenced in your code to understand which elements allow for embedded HTML.
Cross-site Scripting (XSS)
Unsanitized input from the document location flows into a 'src' script element attribute, where it is used to dynamically construct the HTML page on client side. This may result in a DOM Based Cross-Site Scripting attack (DOMXSS).
⇣ Data Flow
href;
href;
url = window.location.href;
url.indexOf('?');
url.substr(startOfQueryString) : '';
substr(startOfQueryString) : '';
queryString = startOfQueryString > -1 ? url.substr(startOfQueryString) : '';
queryString;
'class.js' + queryString;
✓ Fix Analysis
Details
A cross-site scripting attack occurs when the attacker tricks a legitimate web-based application or site to accept a request as originating from a trusted source.
This is done by escaping the context of the web application; the web application then delivers that data to its users along with other trusted dynamic content, without validating it. The browser unknowingly executes malicious script on the client side (through client-side languages; usually JavaScript or HTML) in order to perform actions that are otherwise typically blocked by the browser's Same Origin Policy.
Injecting malicious code is the most prevalent manner by which XSS is exploited; for this reason, escaping characters in order to prevent this manipulation is the top method for securing code against this vulnerability.
Escaping means that the application is coded to mark key characters, and particularly key characters included in user input, to prevent those characters from being interpreted in a dangerous context. For example, in HTML, < can be coded as < and > can be coded as > in order to be interpreted and displayed as themselves in text, while within the code itself, they are used for HTML tags. If malicious content is injected into an application that escapes special characters and that malicious content uses < and > as HTML tags, those characters are nonetheless not interpreted as HTML tags by the browser if they've been correctly escaped in the application code and in this way the attempted attack is diverted.
The most prominent use of XSS is to steal cookies (source: OWASP HttpOnly) and hijack user sessions, but XSS exploits have been used to expose sensitive information, enable access to privileged services and functionality and deliver malware.
Types of attacks
There are a few methods by which XSS can be manipulated:
| Type | Origin | Description |
|---|---|---|
| Stored | Server | The malicious code is inserted in the application (usually as a link) by the attacker. The code is activated every time a user clicks the link. |
| Reflected | Server | The attacker delivers a malicious link externally from the vulnerable web site application to a user. When clicked, malicious code is sent to the vulnerable web site, which reflects the attack back to the user's browser. |
| DOM-based | Client | The attacker forces the user's browser to render a malicious page. The data in the page itself delivers the cross-site scripting data. |
| Mutated | The attacker injects code that appears safe, but is then rewritten and modified by the browser, while parsing the markup. An example is rebalancing unclosed quotation marks or even adding quotation marks to unquoted parameters. |
Affected environments
The following environments are susceptible to an XSS attack:
- Web servers
- Application servers
- Web application environments
Best practices for prevention
This section describes the top best practices designed to specifically protect your code:
- Sanitize data input in an HTTP request before reflecting it back, ensuring all data is validated, filtered or escaped before echoing anything back to the user, such as the values of query parameters during searches.
- Convert special characters such as
?,&,/,<,>and spaces to their respective HTML or URL encoded equivalents. - Give users the option to disable client-side scripts.
- Redirect invalid requests.
- Detect simultaneous logins, including those from two separate IP addresses, and invalidate those sessions.
- Use and enforce a Content Security Policy (source: Wikipedia) to disable any features that might be manipulated for an XSS attack.
- Read the documentation for any of the libraries referenced in your code to understand which elements allow for embedded HTML.
Cross-site Scripting (XSS)
Unsanitized input from the document location flows into a 'src' script element attribute, where it is used to dynamically construct the HTML page on client side. This may result in a DOM Based Cross-Site Scripting attack (DOMXSS).
⇣ Data Flow
href;
href;
url = window.location.href;
url.indexOf('?');
url.substr(startOfQueryString) : '';
substr(startOfQueryString) : '';
queryString = startOfQueryString > -1 ? url.substr(startOfQueryString) : '';
queryString;
'class.js' + queryString;
✓ Fix Analysis
Details
A cross-site scripting attack occurs when the attacker tricks a legitimate web-based application or site to accept a request as originating from a trusted source.
This is done by escaping the context of the web application; the web application then delivers that data to its users along with other trusted dynamic content, without validating it. The browser unknowingly executes malicious script on the client side (through client-side languages; usually JavaScript or HTML) in order to perform actions that are otherwise typically blocked by the browser's Same Origin Policy.
Injecting malicious code is the most prevalent manner by which XSS is exploited; for this reason, escaping characters in order to prevent this manipulation is the top method for securing code against this vulnerability.
Escaping means that the application is coded to mark key characters, and particularly key characters included in user input, to prevent those characters from being interpreted in a dangerous context. For example, in HTML, < can be coded as < and > can be coded as > in order to be interpreted and displayed as themselves in text, while within the code itself, they are used for HTML tags. If malicious content is injected into an application that escapes special characters and that malicious content uses < and > as HTML tags, those characters are nonetheless not interpreted as HTML tags by the browser if they've been correctly escaped in the application code and in this way the attempted attack is diverted.
The most prominent use of XSS is to steal cookies (source: OWASP HttpOnly) and hijack user sessions, but XSS exploits have been used to expose sensitive information, enable access to privileged services and functionality and deliver malware.
Types of attacks
There are a few methods by which XSS can be manipulated:
| Type | Origin | Description |
|---|---|---|
| Stored | Server | The malicious code is inserted in the application (usually as a link) by the attacker. The code is activated every time a user clicks the link. |
| Reflected | Server | The attacker delivers a malicious link externally from the vulnerable web site application to a user. When clicked, malicious code is sent to the vulnerable web site, which reflects the attack back to the user's browser. |
| DOM-based | Client | The attacker forces the user's browser to render a malicious page. The data in the page itself delivers the cross-site scripting data. |
| Mutated | The attacker injects code that appears safe, but is then rewritten and modified by the browser, while parsing the markup. An example is rebalancing unclosed quotation marks or even adding quotation marks to unquoted parameters. |
Affected environments
The following environments are susceptible to an XSS attack:
- Web servers
- Application servers
- Web application environments
Best practices for prevention
This section describes the top best practices designed to specifically protect your code:
- Sanitize data input in an HTTP request before reflecting it back, ensuring all data is validated, filtered or escaped before echoing anything back to the user, such as the values of query parameters during searches.
- Convert special characters such as
?,&,/,<,>and spaces to their respective HTML or URL encoded equivalents. - Give users the option to disable client-side scripts.
- Redirect invalid requests.
- Detect simultaneous logins, including those from two separate IP addresses, and invalidate those sessions.
- Use and enforce a Content Security Policy (source: Wikipedia) to disable any features that might be manipulated for an XSS attack.
- Read the documentation for any of the libraries referenced in your code to understand which elements allow for embedded HTML.
Cross-site Scripting (XSS)
Unsanitized input from the document location flows into a 'src' script element attribute, where it is used to dynamically construct the HTML page on client side. This may result in a DOM Based Cross-Site Scripting attack (DOMXSS).
⇣ Data Flow
href;
href;
url = window.location.href;
url.indexOf('?');
url.substr(startOfQueryString) : '';
substr(startOfQueryString) : '';
queryString = startOfQueryString > -1 ? url.substr(startOfQueryString) : '';
queryString;
'class.js' + queryString;
✓ Fix Analysis
Details
A cross-site scripting attack occurs when the attacker tricks a legitimate web-based application or site to accept a request as originating from a trusted source.
This is done by escaping the context of the web application; the web application then delivers that data to its users along with other trusted dynamic content, without validating it. The browser unknowingly executes malicious script on the client side (through client-side languages; usually JavaScript or HTML) in order to perform actions that are otherwise typically blocked by the browser's Same Origin Policy.
Injecting malicious code is the most prevalent manner by which XSS is exploited; for this reason, escaping characters in order to prevent this manipulation is the top method for securing code against this vulnerability.
Escaping means that the application is coded to mark key characters, and particularly key characters included in user input, to prevent those characters from being interpreted in a dangerous context. For example, in HTML, < can be coded as < and > can be coded as > in order to be interpreted and displayed as themselves in text, while within the code itself, they are used for HTML tags. If malicious content is injected into an application that escapes special characters and that malicious content uses < and > as HTML tags, those characters are nonetheless not interpreted as HTML tags by the browser if they've been correctly escaped in the application code and in this way the attempted attack is diverted.
The most prominent use of XSS is to steal cookies (source: OWASP HttpOnly) and hijack user sessions, but XSS exploits have been used to expose sensitive information, enable access to privileged services and functionality and deliver malware.
Types of attacks
There are a few methods by which XSS can be manipulated:
| Type | Origin | Description |
|---|---|---|
| Stored | Server | The malicious code is inserted in the application (usually as a link) by the attacker. The code is activated every time a user clicks the link. |
| Reflected | Server | The attacker delivers a malicious link externally from the vulnerable web site application to a user. When clicked, malicious code is sent to the vulnerable web site, which reflects the attack back to the user's browser. |
| DOM-based | Client | The attacker forces the user's browser to render a malicious page. The data in the page itself delivers the cross-site scripting data. |
| Mutated | The attacker injects code that appears safe, but is then rewritten and modified by the browser, while parsing the markup. An example is rebalancing unclosed quotation marks or even adding quotation marks to unquoted parameters. |
Affected environments
The following environments are susceptible to an XSS attack:
- Web servers
- Application servers
- Web application environments
Best practices for prevention
This section describes the top best practices designed to specifically protect your code:
- Sanitize data input in an HTTP request before reflecting it back, ensuring all data is validated, filtered or escaped before echoing anything back to the user, such as the values of query parameters during searches.
- Convert special characters such as
?,&,/,<,>and spaces to their respective HTML or URL encoded equivalents. - Give users the option to disable client-side scripts.
- Redirect invalid requests.
- Detect simultaneous logins, including those from two separate IP addresses, and invalidate those sessions.
- Use and enforce a Content Security Policy (source: Wikipedia) to disable any features that might be manipulated for an XSS attack.
- Read the documentation for any of the libraries referenced in your code to understand which elements allow for embedded HTML.
Cross-site Scripting (XSS)
Unsanitized input from the document location flows into a 'src' script element attribute, where it is used to dynamically construct the HTML page on client side. This may result in a DOM Based Cross-Site Scripting attack (DOMXSS).
⇣ Data Flow
href;
href;
url = window.location.href;
url.indexOf('?');
url.substr(startOfQueryString) : '';
substr(startOfQueryString) : '';
queryString = startOfQueryString > -1 ? url.substr(startOfQueryString) : '';
queryString;
'class.js' + queryString;
✓ Fix Analysis
Details
A cross-site scripting attack occurs when the attacker tricks a legitimate web-based application or site to accept a request as originating from a trusted source.
This is done by escaping the context of the web application; the web application then delivers that data to its users along with other trusted dynamic content, without validating it. The browser unknowingly executes malicious script on the client side (through client-side languages; usually JavaScript or HTML) in order to perform actions that are otherwise typically blocked by the browser's Same Origin Policy.
Injecting malicious code is the most prevalent manner by which XSS is exploited; for this reason, escaping characters in order to prevent this manipulation is the top method for securing code against this vulnerability.
Escaping means that the application is coded to mark key characters, and particularly key characters included in user input, to prevent those characters from being interpreted in a dangerous context. For example, in HTML, < can be coded as < and > can be coded as > in order to be interpreted and displayed as themselves in text, while within the code itself, they are used for HTML tags. If malicious content is injected into an application that escapes special characters and that malicious content uses < and > as HTML tags, those characters are nonetheless not interpreted as HTML tags by the browser if they've been correctly escaped in the application code and in this way the attempted attack is diverted.
The most prominent use of XSS is to steal cookies (source: OWASP HttpOnly) and hijack user sessions, but XSS exploits have been used to expose sensitive information, enable access to privileged services and functionality and deliver malware.
Types of attacks
There are a few methods by which XSS can be manipulated:
| Type | Origin | Description |
|---|---|---|
| Stored | Server | The malicious code is inserted in the application (usually as a link) by the attacker. The code is activated every time a user clicks the link. |
| Reflected | Server | The attacker delivers a malicious link externally from the vulnerable web site application to a user. When clicked, malicious code is sent to the vulnerable web site, which reflects the attack back to the user's browser. |
| DOM-based | Client | The attacker forces the user's browser to render a malicious page. The data in the page itself delivers the cross-site scripting data. |
| Mutated | The attacker injects code that appears safe, but is then rewritten and modified by the browser, while parsing the markup. An example is rebalancing unclosed quotation marks or even adding quotation marks to unquoted parameters. |
Affected environments
The following environments are susceptible to an XSS attack:
- Web servers
- Application servers
- Web application environments
Best practices for prevention
This section describes the top best practices designed to specifically protect your code:
- Sanitize data input in an HTTP request before reflecting it back, ensuring all data is validated, filtered or escaped before echoing anything back to the user, such as the values of query parameters during searches.
- Convert special characters such as
?,&,/,<,>and spaces to their respective HTML or URL encoded equivalents. - Give users the option to disable client-side scripts.
- Redirect invalid requests.
- Detect simultaneous logins, including those from two separate IP addresses, and invalidate those sessions.
- Use and enforce a Content Security Policy (source: Wikipedia) to disable any features that might be manipulated for an XSS attack.
- Read the documentation for any of the libraries referenced in your code to understand which elements allow for embedded HTML.
Cross-site Scripting (XSS)
Unsanitized input from the document location flows into a 'src' script element attribute, where it is used to dynamically construct the HTML page on client side. This may result in a DOM Based Cross-Site Scripting attack (DOMXSS).
⇣ Data Flow
href;
href;
url = window.location.href;
url.indexOf('?');
url.substr(startOfQueryString) : '';
substr(startOfQueryString) : '';
queryString = startOfQueryString > -1 ? url.substr(startOfQueryString) : '';
queryString;
'class.js' + queryString;
✓ Fix Analysis
Details
A cross-site scripting attack occurs when the attacker tricks a legitimate web-based application or site to accept a request as originating from a trusted source.
This is done by escaping the context of the web application; the web application then delivers that data to its users along with other trusted dynamic content, without validating it. The browser unknowingly executes malicious script on the client side (through client-side languages; usually JavaScript or HTML) in order to perform actions that are otherwise typically blocked by the browser's Same Origin Policy.
Injecting malicious code is the most prevalent manner by which XSS is exploited; for this reason, escaping characters in order to prevent this manipulation is the top method for securing code against this vulnerability.
Escaping means that the application is coded to mark key characters, and particularly key characters included in user input, to prevent those characters from being interpreted in a dangerous context. For example, in HTML, < can be coded as < and > can be coded as > in order to be interpreted and displayed as themselves in text, while within the code itself, they are used for HTML tags. If malicious content is injected into an application that escapes special characters and that malicious content uses < and > as HTML tags, those characters are nonetheless not interpreted as HTML tags by the browser if they've been correctly escaped in the application code and in this way the attempted attack is diverted.
The most prominent use of XSS is to steal cookies (source: OWASP HttpOnly) and hijack user sessions, but XSS exploits have been used to expose sensitive information, enable access to privileged services and functionality and deliver malware.
Types of attacks
There are a few methods by which XSS can be manipulated:
| Type | Origin | Description |
|---|---|---|
| Stored | Server | The malicious code is inserted in the application (usually as a link) by the attacker. The code is activated every time a user clicks the link. |
| Reflected | Server | The attacker delivers a malicious link externally from the vulnerable web site application to a user. When clicked, malicious code is sent to the vulnerable web site, which reflects the attack back to the user's browser. |
| DOM-based | Client | The attacker forces the user's browser to render a malicious page. The data in the page itself delivers the cross-site scripting data. |
| Mutated | The attacker injects code that appears safe, but is then rewritten and modified by the browser, while parsing the markup. An example is rebalancing unclosed quotation marks or even adding quotation marks to unquoted parameters. |
Affected environments
The following environments are susceptible to an XSS attack:
- Web servers
- Application servers
- Web application environments
Best practices for prevention
This section describes the top best practices designed to specifically protect your code:
- Sanitize data input in an HTTP request before reflecting it back, ensuring all data is validated, filtered or escaped before echoing anything back to the user, such as the values of query parameters during searches.
- Convert special characters such as
?,&,/,<,>and spaces to their respective HTML or URL encoded equivalents. - Give users the option to disable client-side scripts.
- Redirect invalid requests.
- Detect simultaneous logins, including those from two separate IP addresses, and invalidate those sessions.
- Use and enforce a Content Security Policy (source: Wikipedia) to disable any features that might be manipulated for an XSS attack.
- Read the documentation for any of the libraries referenced in your code to understand which elements allow for embedded HTML.
Cross-site Scripting (XSS)
Unsanitized input from the document location flows into a 'src' script element attribute, where it is used to dynamically construct the HTML page on client side. This may result in a DOM Based Cross-Site Scripting attack (DOMXSS).
⇣ Data Flow
href;
href;
url = window.location.href;
url.indexOf('?');
url.substr(startOfQueryString) : '';
substr(startOfQueryString) : '';
queryString = startOfQueryString > -1 ? url.substr(startOfQueryString) : '';
queryString;
'main.js' + queryString;
✓ Fix Analysis
Details
A cross-site scripting attack occurs when the attacker tricks a legitimate web-based application or site to accept a request as originating from a trusted source.
This is done by escaping the context of the web application; the web application then delivers that data to its users along with other trusted dynamic content, without validating it. The browser unknowingly executes malicious script on the client side (through client-side languages; usually JavaScript or HTML) in order to perform actions that are otherwise typically blocked by the browser's Same Origin Policy.
Injecting malicious code is the most prevalent manner by which XSS is exploited; for this reason, escaping characters in order to prevent this manipulation is the top method for securing code against this vulnerability.
Escaping means that the application is coded to mark key characters, and particularly key characters included in user input, to prevent those characters from being interpreted in a dangerous context. For example, in HTML, < can be coded as < and > can be coded as > in order to be interpreted and displayed as themselves in text, while within the code itself, they are used for HTML tags. If malicious content is injected into an application that escapes special characters and that malicious content uses < and > as HTML tags, those characters are nonetheless not interpreted as HTML tags by the browser if they've been correctly escaped in the application code and in this way the attempted attack is diverted.
The most prominent use of XSS is to steal cookies (source: OWASP HttpOnly) and hijack user sessions, but XSS exploits have been used to expose sensitive information, enable access to privileged services and functionality and deliver malware.
Types of attacks
There are a few methods by which XSS can be manipulated:
| Type | Origin | Description |
|---|---|---|
| Stored | Server | The malicious code is inserted in the application (usually as a link) by the attacker. The code is activated every time a user clicks the link. |
| Reflected | Server | The attacker delivers a malicious link externally from the vulnerable web site application to a user. When clicked, malicious code is sent to the vulnerable web site, which reflects the attack back to the user's browser. |
| DOM-based | Client | The attacker forces the user's browser to render a malicious page. The data in the page itself delivers the cross-site scripting data. |
| Mutated | The attacker injects code that appears safe, but is then rewritten and modified by the browser, while parsing the markup. An example is rebalancing unclosed quotation marks or even adding quotation marks to unquoted parameters. |
Affected environments
The following environments are susceptible to an XSS attack:
- Web servers
- Application servers
- Web application environments
Best practices for prevention
This section describes the top best practices designed to specifically protect your code:
- Sanitize data input in an HTTP request before reflecting it back, ensuring all data is validated, filtered or escaped before echoing anything back to the user, such as the values of query parameters during searches.
- Convert special characters such as
?,&,/,<,>and spaces to their respective HTML or URL encoded equivalents. - Give users the option to disable client-side scripts.
- Redirect invalid requests.
- Detect simultaneous logins, including those from two separate IP addresses, and invalidate those sessions.
- Use and enforce a Content Security Policy (source: Wikipedia) to disable any features that might be manipulated for an XSS attack.
- Read the documentation for any of the libraries referenced in your code to understand which elements allow for embedded HTML.
Cross-site Scripting (XSS)
Unsanitized input from the document location flows into a 'src' script element attribute, where it is used to dynamically construct the HTML page on client side. This may result in a DOM Based Cross-Site Scripting attack (DOMXSS).
⇣ Data Flow
href;
href;
url = window.location.href;
url.indexOf('?');
url.substr(startOfQueryString) : '';
substr(startOfQueryString) : '';
queryString = startOfQueryString > -1 ? url.substr(startOfQueryString) : '';
queryString;
'class.js' + queryString;
✓ Fix Analysis
Details
A cross-site scripting attack occurs when the attacker tricks a legitimate web-based application or site to accept a request as originating from a trusted source.
This is done by escaping the context of the web application; the web application then delivers that data to its users along with other trusted dynamic content, without validating it. The browser unknowingly executes malicious script on the client side (through client-side languages; usually JavaScript or HTML) in order to perform actions that are otherwise typically blocked by the browser's Same Origin Policy.
Injecting malicious code is the most prevalent manner by which XSS is exploited; for this reason, escaping characters in order to prevent this manipulation is the top method for securing code against this vulnerability.
Escaping means that the application is coded to mark key characters, and particularly key characters included in user input, to prevent those characters from being interpreted in a dangerous context. For example, in HTML, < can be coded as < and > can be coded as > in order to be interpreted and displayed as themselves in text, while within the code itself, they are used for HTML tags. If malicious content is injected into an application that escapes special characters and that malicious content uses < and > as HTML tags, those characters are nonetheless not interpreted as HTML tags by the browser if they've been correctly escaped in the application code and in this way the attempted attack is diverted.
The most prominent use of XSS is to steal cookies (source: OWASP HttpOnly) and hijack user sessions, but XSS exploits have been used to expose sensitive information, enable access to privileged services and functionality and deliver malware.
Types of attacks
There are a few methods by which XSS can be manipulated:
| Type | Origin | Description |
|---|---|---|
| Stored | Server | The malicious code is inserted in the application (usually as a link) by the attacker. The code is activated every time a user clicks the link. |
| Reflected | Server | The attacker delivers a malicious link externally from the vulnerable web site application to a user. When clicked, malicious code is sent to the vulnerable web site, which reflects the attack back to the user's browser. |
| DOM-based | Client | The attacker forces the user's browser to render a malicious page. The data in the page itself delivers the cross-site scripting data. |
| Mutated | The attacker injects code that appears safe, but is then rewritten and modified by the browser, while parsing the markup. An example is rebalancing unclosed quotation marks or even adding quotation marks to unquoted parameters. |
Affected environments
The following environments are susceptible to an XSS attack:
- Web servers
- Application servers
- Web application environments
Best practices for prevention
This section describes the top best practices designed to specifically protect your code:
- Sanitize data input in an HTTP request before reflecting it back, ensuring all data is validated, filtered or escaped before echoing anything back to the user, such as the values of query parameters during searches.
- Convert special characters such as
?,&,/,<,>and spaces to their respective HTML or URL encoded equivalents. - Give users the option to disable client-side scripts.
- Redirect invalid requests.
- Detect simultaneous logins, including those from two separate IP addresses, and invalidate those sessions.
- Use and enforce a Content Security Policy (source: Wikipedia) to disable any features that might be manipulated for an XSS attack.
- Read the documentation for any of the libraries referenced in your code to understand which elements allow for embedded HTML.
Cross-site Scripting (XSS)
Unsanitized input from the document location flows into a 'src' script element attribute, where it is used to dynamically construct the HTML page on client side. This may result in a DOM Based Cross-Site Scripting attack (DOMXSS).
⇣ Data Flow
href;
href;
url = window.location.href;
url.indexOf('?');
url.substr(startOfQueryString) : '';
substr(startOfQueryString) : '';
queryString = startOfQueryString > -1 ? url.substr(startOfQueryString) : '';
queryString;
'class.js' + queryString;
✓ Fix Analysis
Details
A cross-site scripting attack occurs when the attacker tricks a legitimate web-based application or site to accept a request as originating from a trusted source.
This is done by escaping the context of the web application; the web application then delivers that data to its users along with other trusted dynamic content, without validating it. The browser unknowingly executes malicious script on the client side (through client-side languages; usually JavaScript or HTML) in order to perform actions that are otherwise typically blocked by the browser's Same Origin Policy.
Injecting malicious code is the most prevalent manner by which XSS is exploited; for this reason, escaping characters in order to prevent this manipulation is the top method for securing code against this vulnerability.
Escaping means that the application is coded to mark key characters, and particularly key characters included in user input, to prevent those characters from being interpreted in a dangerous context. For example, in HTML, < can be coded as < and > can be coded as > in order to be interpreted and displayed as themselves in text, while within the code itself, they are used for HTML tags. If malicious content is injected into an application that escapes special characters and that malicious content uses < and > as HTML tags, those characters are nonetheless not interpreted as HTML tags by the browser if they've been correctly escaped in the application code and in this way the attempted attack is diverted.
The most prominent use of XSS is to steal cookies (source: OWASP HttpOnly) and hijack user sessions, but XSS exploits have been used to expose sensitive information, enable access to privileged services and functionality and deliver malware.
Types of attacks
There are a few methods by which XSS can be manipulated:
| Type | Origin | Description |
|---|---|---|
| Stored | Server | The malicious code is inserted in the application (usually as a link) by the attacker. The code is activated every time a user clicks the link. |
| Reflected | Server | The attacker delivers a malicious link externally from the vulnerable web site application to a user. When clicked, malicious code is sent to the vulnerable web site, which reflects the attack back to the user's browser. |
| DOM-based | Client | The attacker forces the user's browser to render a malicious page. The data in the page itself delivers the cross-site scripting data. |
| Mutated | The attacker injects code that appears safe, but is then rewritten and modified by the browser, while parsing the markup. An example is rebalancing unclosed quotation marks or even adding quotation marks to unquoted parameters. |
Affected environments
The following environments are susceptible to an XSS attack:
- Web servers
- Application servers
- Web application environments
Best practices for prevention
This section describes the top best practices designed to specifically protect your code:
- Sanitize data input in an HTTP request before reflecting it back, ensuring all data is validated, filtered or escaped before echoing anything back to the user, such as the values of query parameters during searches.
- Convert special characters such as
?,&,/,<,>and spaces to their respective HTML or URL encoded equivalents. - Give users the option to disable client-side scripts.
- Redirect invalid requests.
- Detect simultaneous logins, including those from two separate IP addresses, and invalidate those sessions.
- Use and enforce a Content Security Policy (source: Wikipedia) to disable any features that might be manipulated for an XSS attack.
- Read the documentation for any of the libraries referenced in your code to understand which elements allow for embedded HTML.
Cross-site Scripting (XSS)
Unsanitized input from the document location flows into a 'src' script element attribute, where it is used to dynamically construct the HTML page on client side. This may result in a DOM Based Cross-Site Scripting attack (DOMXSS).
⇣ Data Flow
href;
href;
url = window.location.href;
url.indexOf('?');
url.substr(startOfQueryString) : '';
substr(startOfQueryString) : '';
queryString = startOfQueryString > -1 ? url.substr(startOfQueryString) : '';
queryString;
'class.js' + queryString;
✓ Fix Analysis
Details
A cross-site scripting attack occurs when the attacker tricks a legitimate web-based application or site to accept a request as originating from a trusted source.
This is done by escaping the context of the web application; the web application then delivers that data to its users along with other trusted dynamic content, without validating it. The browser unknowingly executes malicious script on the client side (through client-side languages; usually JavaScript or HTML) in order to perform actions that are otherwise typically blocked by the browser's Same Origin Policy.
Injecting malicious code is the most prevalent manner by which XSS is exploited; for this reason, escaping characters in order to prevent this manipulation is the top method for securing code against this vulnerability.
Escaping means that the application is coded to mark key characters, and particularly key characters included in user input, to prevent those characters from being interpreted in a dangerous context. For example, in HTML, < can be coded as < and > can be coded as > in order to be interpreted and displayed as themselves in text, while within the code itself, they are used for HTML tags. If malicious content is injected into an application that escapes special characters and that malicious content uses < and > as HTML tags, those characters are nonetheless not interpreted as HTML tags by the browser if they've been correctly escaped in the application code and in this way the attempted attack is diverted.
The most prominent use of XSS is to steal cookies (source: OWASP HttpOnly) and hijack user sessions, but XSS exploits have been used to expose sensitive information, enable access to privileged services and functionality and deliver malware.
Types of attacks
There are a few methods by which XSS can be manipulated:
| Type | Origin | Description |
|---|---|---|
| Stored | Server | The malicious code is inserted in the application (usually as a link) by the attacker. The code is activated every time a user clicks the link. |
| Reflected | Server | The attacker delivers a malicious link externally from the vulnerable web site application to a user. When clicked, malicious code is sent to the vulnerable web site, which reflects the attack back to the user's browser. |
| DOM-based | Client | The attacker forces the user's browser to render a malicious page. The data in the page itself delivers the cross-site scripting data. |
| Mutated | The attacker injects code that appears safe, but is then rewritten and modified by the browser, while parsing the markup. An example is rebalancing unclosed quotation marks or even adding quotation marks to unquoted parameters. |
Affected environments
The following environments are susceptible to an XSS attack:
- Web servers
- Application servers
- Web application environments
Best practices for prevention
This section describes the top best practices designed to specifically protect your code:
- Sanitize data input in an HTTP request before reflecting it back, ensuring all data is validated, filtered or escaped before echoing anything back to the user, such as the values of query parameters during searches.
- Convert special characters such as
?,&,/,<,>and spaces to their respective HTML or URL encoded equivalents. - Give users the option to disable client-side scripts.
- Redirect invalid requests.
- Detect simultaneous logins, including those from two separate IP addresses, and invalidate those sessions.
- Use and enforce a Content Security Policy (source: Wikipedia) to disable any features that might be manipulated for an XSS attack.
- Read the documentation for any of the libraries referenced in your code to understand which elements allow for embedded HTML.
Cross-site Scripting (XSS)
Unsanitized input from the document location flows into a 'src' script element attribute, where it is used to dynamically construct the HTML page on client side. This may result in a DOM Based Cross-Site Scripting attack (DOMXSS).
⇣ Data Flow
href;
href;
url = window.location.href;
url.indexOf('?');
url.substr(startOfQueryString) : '';
substr(startOfQueryString) : '';
queryString = startOfQueryString > -1 ? url.substr(startOfQueryString) : '';
queryString;
'class.js' + queryString;
✓ Fix Analysis
Details
A cross-site scripting attack occurs when the attacker tricks a legitimate web-based application or site to accept a request as originating from a trusted source.
This is done by escaping the context of the web application; the web application then delivers that data to its users along with other trusted dynamic content, without validating it. The browser unknowingly executes malicious script on the client side (through client-side languages; usually JavaScript or HTML) in order to perform actions that are otherwise typically blocked by the browser's Same Origin Policy.
Injecting malicious code is the most prevalent manner by which XSS is exploited; for this reason, escaping characters in order to prevent this manipulation is the top method for securing code against this vulnerability.
Escaping means that the application is coded to mark key characters, and particularly key characters included in user input, to prevent those characters from being interpreted in a dangerous context. For example, in HTML, < can be coded as < and > can be coded as > in order to be interpreted and displayed as themselves in text, while within the code itself, they are used for HTML tags. If malicious content is injected into an application that escapes special characters and that malicious content uses < and > as HTML tags, those characters are nonetheless not interpreted as HTML tags by the browser if they've been correctly escaped in the application code and in this way the attempted attack is diverted.
The most prominent use of XSS is to steal cookies (source: OWASP HttpOnly) and hijack user sessions, but XSS exploits have been used to expose sensitive information, enable access to privileged services and functionality and deliver malware.
Types of attacks
There are a few methods by which XSS can be manipulated:
| Type | Origin | Description |
|---|---|---|
| Stored | Server | The malicious code is inserted in the application (usually as a link) by the attacker. The code is activated every time a user clicks the link. |
| Reflected | Server | The attacker delivers a malicious link externally from the vulnerable web site application to a user. When clicked, malicious code is sent to the vulnerable web site, which reflects the attack back to the user's browser. |
| DOM-based | Client | The attacker forces the user's browser to render a malicious page. The data in the page itself delivers the cross-site scripting data. |
| Mutated | The attacker injects code that appears safe, but is then rewritten and modified by the browser, while parsing the markup. An example is rebalancing unclosed quotation marks or even adding quotation marks to unquoted parameters. |
Affected environments
The following environments are susceptible to an XSS attack:
- Web servers
- Application servers
- Web application environments
Best practices for prevention
This section describes the top best practices designed to specifically protect your code:
- Sanitize data input in an HTTP request before reflecting it back, ensuring all data is validated, filtered or escaped before echoing anything back to the user, such as the values of query parameters during searches.
- Convert special characters such as
?,&,/,<,>and spaces to their respective HTML or URL encoded equivalents. - Give users the option to disable client-side scripts.
- Redirect invalid requests.
- Detect simultaneous logins, including those from two separate IP addresses, and invalidate those sessions.
- Use and enforce a Content Security Policy (source: Wikipedia) to disable any features that might be manipulated for an XSS attack.
- Read the documentation for any of the libraries referenced in your code to understand which elements allow for embedded HTML.
Cross-site Scripting (XSS)
Unsanitized input from the document location flows into a 'src' script element attribute, where it is used to dynamically construct the HTML page on client side. This may result in a DOM Based Cross-Site Scripting attack (DOMXSS).
⇣ Data Flow
href;
href;
url = window.location.href;
url.indexOf('?');
url.substr(startOfQueryString) : '';
substr(startOfQueryString) : '';
queryString = startOfQueryString > -1 ? url.substr(startOfQueryString) : '';
queryString;
'class.js' + queryString;
✓ Fix Analysis
Details
A cross-site scripting attack occurs when the attacker tricks a legitimate web-based application or site to accept a request as originating from a trusted source.
This is done by escaping the context of the web application; the web application then delivers that data to its users along with other trusted dynamic content, without validating it. The browser unknowingly executes malicious script on the client side (through client-side languages; usually JavaScript or HTML) in order to perform actions that are otherwise typically blocked by the browser's Same Origin Policy.
Injecting malicious code is the most prevalent manner by which XSS is exploited; for this reason, escaping characters in order to prevent this manipulation is the top method for securing code against this vulnerability.
Escaping means that the application is coded to mark key characters, and particularly key characters included in user input, to prevent those characters from being interpreted in a dangerous context. For example, in HTML, < can be coded as < and > can be coded as > in order to be interpreted and displayed as themselves in text, while within the code itself, they are used for HTML tags. If malicious content is injected into an application that escapes special characters and that malicious content uses < and > as HTML tags, those characters are nonetheless not interpreted as HTML tags by the browser if they've been correctly escaped in the application code and in this way the attempted attack is diverted.
The most prominent use of XSS is to steal cookies (source: OWASP HttpOnly) and hijack user sessions, but XSS exploits have been used to expose sensitive information, enable access to privileged services and functionality and deliver malware.
Types of attacks
There are a few methods by which XSS can be manipulated:
| Type | Origin | Description |
|---|---|---|
| Stored | Server | The malicious code is inserted in the application (usually as a link) by the attacker. The code is activated every time a user clicks the link. |
| Reflected | Server | The attacker delivers a malicious link externally from the vulnerable web site application to a user. When clicked, malicious code is sent to the vulnerable web site, which reflects the attack back to the user's browser. |
| DOM-based | Client | The attacker forces the user's browser to render a malicious page. The data in the page itself delivers the cross-site scripting data. |
| Mutated | The attacker injects code that appears safe, but is then rewritten and modified by the browser, while parsing the markup. An example is rebalancing unclosed quotation marks or even adding quotation marks to unquoted parameters. |
Affected environments
The following environments are susceptible to an XSS attack:
- Web servers
- Application servers
- Web application environments
Best practices for prevention
This section describes the top best practices designed to specifically protect your code:
- Sanitize data input in an HTTP request before reflecting it back, ensuring all data is validated, filtered or escaped before echoing anything back to the user, such as the values of query parameters during searches.
- Convert special characters such as
?,&,/,<,>and spaces to their respective HTML or URL encoded equivalents. - Give users the option to disable client-side scripts.
- Redirect invalid requests.
- Detect simultaneous logins, including those from two separate IP addresses, and invalidate those sessions.
- Use and enforce a Content Security Policy (source: Wikipedia) to disable any features that might be manipulated for an XSS attack.
- Read the documentation for any of the libraries referenced in your code to understand which elements allow for embedded HTML.
Cross-site Scripting (XSS)
Unsanitized input from the document location flows into a 'src' script element attribute, where it is used to dynamically construct the HTML page on client side. This may result in a DOM Based Cross-Site Scripting attack (DOMXSS).
⇣ Data Flow
href;
href;
url = window.location.href;
url.indexOf('?');
url.substr(startOfQueryString) : '';
substr(startOfQueryString) : '';
queryString = startOfQueryString > -1 ? url.substr(startOfQueryString) : '';
queryString;
'class.js' + queryString;
✓ Fix Analysis
Details
A cross-site scripting attack occurs when the attacker tricks a legitimate web-based application or site to accept a request as originating from a trusted source.
This is done by escaping the context of the web application; the web application then delivers that data to its users along with other trusted dynamic content, without validating it. The browser unknowingly executes malicious script on the client side (through client-side languages; usually JavaScript or HTML) in order to perform actions that are otherwise typically blocked by the browser's Same Origin Policy.
Injecting malicious code is the most prevalent manner by which XSS is exploited; for this reason, escaping characters in order to prevent this manipulation is the top method for securing code against this vulnerability.
Escaping means that the application is coded to mark key characters, and particularly key characters included in user input, to prevent those characters from being interpreted in a dangerous context. For example, in HTML, < can be coded as < and > can be coded as > in order to be interpreted and displayed as themselves in text, while within the code itself, they are used for HTML tags. If malicious content is injected into an application that escapes special characters and that malicious content uses < and > as HTML tags, those characters are nonetheless not interpreted as HTML tags by the browser if they've been correctly escaped in the application code and in this way the attempted attack is diverted.
The most prominent use of XSS is to steal cookies (source: OWASP HttpOnly) and hijack user sessions, but XSS exploits have been used to expose sensitive information, enable access to privileged services and functionality and deliver malware.
Types of attacks
There are a few methods by which XSS can be manipulated:
| Type | Origin | Description |
|---|---|---|
| Stored | Server | The malicious code is inserted in the application (usually as a link) by the attacker. The code is activated every time a user clicks the link. |
| Reflected | Server | The attacker delivers a malicious link externally from the vulnerable web site application to a user. When clicked, malicious code is sent to the vulnerable web site, which reflects the attack back to the user's browser. |
| DOM-based | Client | The attacker forces the user's browser to render a malicious page. The data in the page itself delivers the cross-site scripting data. |
| Mutated | The attacker injects code that appears safe, but is then rewritten and modified by the browser, while parsing the markup. An example is rebalancing unclosed quotation marks or even adding quotation marks to unquoted parameters. |
Affected environments
The following environments are susceptible to an XSS attack:
- Web servers
- Application servers
- Web application environments
Best practices for prevention
This section describes the top best practices designed to specifically protect your code:
- Sanitize data input in an HTTP request before reflecting it back, ensuring all data is validated, filtered or escaped before echoing anything back to the user, such as the values of query parameters during searches.
- Convert special characters such as
?,&,/,<,>and spaces to their respective HTML or URL encoded equivalents. - Give users the option to disable client-side scripts.
- Redirect invalid requests.
- Detect simultaneous logins, including those from two separate IP addresses, and invalidate those sessions.
- Use and enforce a Content Security Policy (source: Wikipedia) to disable any features that might be manipulated for an XSS attack.
- Read the documentation for any of the libraries referenced in your code to understand which elements allow for embedded HTML.
Use of Password Hash With Insufficient Computational Effort
hashlib.sha1 is insecure. Consider changing it to a secure hashing algorithm.
⇣ Data Flow
hashlib.sha1(string)
✓ Fix Analysis
Details
Sensitive information should never be stored in plain text, since this makes it very easy for unauthorized users, whether malicious insiders or outside attackers, to access. Hashing methods are used to make stored passwords and other sensitive data unreadable to users. For example, when a password is defined for the first time, it is hashed and then stored. The next time that user attempts to log on, the password they enter is hashed following the same procedure and compared with the stored value. In this way, the original password never needs to be stored in the system.
Hashing is a one-way scheme, meaning a hashed password cannot be reverse engineered. However, if an outdated or custom programmed hashing scheme is used, it becomes simple for an attacker with powerful modern computing power to gain access to the hashes used. This opens up access to all stored password information, leading to breached security. Therefore, it is essential for developers to understand modern, secure password hashing techniques.
Best practices for prevention
- Use strong standard algorithms for hashing rather than simpler but outdated methods or DIY hashing schemes, which may have inherent weaknesses.
- Use modular design for all code dealing with hashing so it can be swapped out as security standards change over time.
- Use salting in combination with hashing (While this places more demands on resources, it is an essential step for tighter security.).
- Implement zero-trust architecture to ensure that access to password data is granted only for legitimate business purposes.
- Increase developer awareness of current standards in data security and cryptography.
Use of Password Hash With Insufficient Computational Effort
hashlib.sha1 is insecure. Consider changing it to a secure hashing algorithm.
⇣ Data Flow
sha1(data).hexdigest()
✓ Fix Analysis
Details
Sensitive information should never be stored in plain text, since this makes it very easy for unauthorized users, whether malicious insiders or outside attackers, to access. Hashing methods are used to make stored passwords and other sensitive data unreadable to users. For example, when a password is defined for the first time, it is hashed and then stored. The next time that user attempts to log on, the password they enter is hashed following the same procedure and compared with the stored value. In this way, the original password never needs to be stored in the system.
Hashing is a one-way scheme, meaning a hashed password cannot be reverse engineered. However, if an outdated or custom programmed hashing scheme is used, it becomes simple for an attacker with powerful modern computing power to gain access to the hashes used. This opens up access to all stored password information, leading to breached security. Therefore, it is essential for developers to understand modern, secure password hashing techniques.
Best practices for prevention
- Use strong standard algorithms for hashing rather than simpler but outdated methods or DIY hashing schemes, which may have inherent weaknesses.
- Use modular design for all code dealing with hashing so it can be swapped out as security standards change over time.
- Use salting in combination with hashing (While this places more demands on resources, it is an essential step for tighter security.).
- Implement zero-trust architecture to ensure that access to password data is granted only for legitimate business purposes.
- Increase developer awareness of current standards in data security and cryptography.
Use of Password Hash With Insufficient Computational Effort
hashlib.sha1 is insecure. Consider changing it to a secure hashing algorithm.
⇣ Data Flow
sha1(name.encode("utf-8")).hexdigest()
✓ Fix Analysis
Details
Sensitive information should never be stored in plain text, since this makes it very easy for unauthorized users, whether malicious insiders or outside attackers, to access. Hashing methods are used to make stored passwords and other sensitive data unreadable to users. For example, when a password is defined for the first time, it is hashed and then stored. The next time that user attempts to log on, the password they enter is hashed following the same procedure and compared with the stored value. In this way, the original password never needs to be stored in the system.
Hashing is a one-way scheme, meaning a hashed password cannot be reverse engineered. However, if an outdated or custom programmed hashing scheme is used, it becomes simple for an attacker with powerful modern computing power to gain access to the hashes used. This opens up access to all stored password information, leading to breached security. Therefore, it is essential for developers to understand modern, secure password hashing techniques.
Best practices for prevention
- Use strong standard algorithms for hashing rather than simpler but outdated methods or DIY hashing schemes, which may have inherent weaknesses.
- Use modular design for all code dealing with hashing so it can be swapped out as security standards change over time.
- Use salting in combination with hashing (While this places more demands on resources, it is an essential step for tighter security.).
- Implement zero-trust architecture to ensure that access to password data is granted only for legitimate business purposes.
- Increase developer awareness of current standards in data security and cryptography.
Use of Password Hash With Insufficient Computational Effort
hashlib.sha1 is insecure. Consider changing it to a secure hashing algorithm.
⇣ Data Flow
hashlib.sha1(string)
✓ Fix Analysis
Details
Sensitive information should never be stored in plain text, since this makes it very easy for unauthorized users, whether malicious insiders or outside attackers, to access. Hashing methods are used to make stored passwords and other sensitive data unreadable to users. For example, when a password is defined for the first time, it is hashed and then stored. The next time that user attempts to log on, the password they enter is hashed following the same procedure and compared with the stored value. In this way, the original password never needs to be stored in the system.
Hashing is a one-way scheme, meaning a hashed password cannot be reverse engineered. However, if an outdated or custom programmed hashing scheme is used, it becomes simple for an attacker with powerful modern computing power to gain access to the hashes used. This opens up access to all stored password information, leading to breached security. Therefore, it is essential for developers to understand modern, secure password hashing techniques.
Best practices for prevention
- Use strong standard algorithms for hashing rather than simpler but outdated methods or DIY hashing schemes, which may have inherent weaknesses.
- Use modular design for all code dealing with hashing so it can be swapped out as security standards change over time.
- Use salting in combination with hashing (While this places more demands on resources, it is an essential step for tighter security.).
- Implement zero-trust architecture to ensure that access to password data is granted only for legitimate business purposes.
- Increase developer awareness of current standards in data security and cryptography.
Use of Password Hash With Insufficient Computational Effort
hashlib.md5 is insecure. Consider changing it to a secure hashing algorithm.
⇣ Data Flow
hashlib.md5(content).hexdigest()
✓ Fix Analysis
Details
Sensitive information should never be stored in plain text, since this makes it very easy for unauthorized users, whether malicious insiders or outside attackers, to access. Hashing methods are used to make stored passwords and other sensitive data unreadable to users. For example, when a password is defined for the first time, it is hashed and then stored. The next time that user attempts to log on, the password they enter is hashed following the same procedure and compared with the stored value. In this way, the original password never needs to be stored in the system.
Hashing is a one-way scheme, meaning a hashed password cannot be reverse engineered. However, if an outdated or custom programmed hashing scheme is used, it becomes simple for an attacker with powerful modern computing power to gain access to the hashes used. This opens up access to all stored password information, leading to breached security. Therefore, it is essential for developers to understand modern, secure password hashing techniques.
Best practices for prevention
- Use strong standard algorithms for hashing rather than simpler but outdated methods or DIY hashing schemes, which may have inherent weaknesses.
- Use modular design for all code dealing with hashing so it can be swapped out as security standards change over time.
- Use salting in combination with hashing (While this places more demands on resources, it is an essential step for tighter security.).
- Implement zero-trust architecture to ensure that access to password data is granted only for legitimate business purposes.
- Increase developer awareness of current standards in data security and cryptography.
Use of Password Hash With Insufficient Computational Effort
hashlib.md5 is insecure. Consider changing it to a secure hashing algorithm.
⇣ Data Flow
hashlib.md5(file_data).hexdigest()
✓ Fix Analysis
Details
Sensitive information should never be stored in plain text, since this makes it very easy for unauthorized users, whether malicious insiders or outside attackers, to access. Hashing methods are used to make stored passwords and other sensitive data unreadable to users. For example, when a password is defined for the first time, it is hashed and then stored. The next time that user attempts to log on, the password they enter is hashed following the same procedure and compared with the stored value. In this way, the original password never needs to be stored in the system.
Hashing is a one-way scheme, meaning a hashed password cannot be reverse engineered. However, if an outdated or custom programmed hashing scheme is used, it becomes simple for an attacker with powerful modern computing power to gain access to the hashes used. This opens up access to all stored password information, leading to breached security. Therefore, it is essential for developers to understand modern, secure password hashing techniques.
Best practices for prevention
- Use strong standard algorithms for hashing rather than simpler but outdated methods or DIY hashing schemes, which may have inherent weaknesses.
- Use modular design for all code dealing with hashing so it can be swapped out as security standards change over time.
- Use salting in combination with hashing (While this places more demands on resources, it is an essential step for tighter security.).
- Implement zero-trust architecture to ensure that access to password data is granted only for legitimate business purposes.
- Increase developer awareness of current standards in data security and cryptography.
Use of Hardcoded Credentials
Do not hardcode passwords in code. Found hardcoded password used in a dictionary key.
⇣ Data Flow
'admin123'}
✓ Fix Analysis
Details
Developers may use hardcoded credentials for convenience when coding in order to simplify their workflow. While they are responsible for removing these before production, occasionally this task may fall through the cracks. This also becomes a maintenance challenge when credentials are re-used across multiple applications.
Once attackers gain access, they may take advantage of privilege level to remove or alter data, take down a site or app, or hold any of the above for ransom. The risk across multiple similar projects is even greater. If code containing the credentials is reused across multiple projects, they will all be compromised.
Best practices for prevention
- Plan software architecture such that keys and passwords are always stored outside the code, wherever possible.
- Plan encryption into software architecture for all credential information and ensure proper handling of keys, credentials, and passwords.
- Prompt for a secure password on first login rather than hard-code a default password.
- If a hardcoded password or credential must be used, limit its use, for example, to system console users rather than via the network.
- Use strong hashes for inbound password authentication, ideally with randomly assigned salts to increase the difficulty level in case of brute-force attack.
Use of Hardcoded Credentials
Do not hardcode credentials in code. Found hardcoded credential used in here.
⇣ Data Flow
"****"
✓ Fix Analysis
Details
Developers may use hardcoded credentials for convenience when coding in order to simplify their workflow. While they are responsible for removing these before production, occasionally this task may fall through the cracks. This also becomes a maintenance challenge when credentials are re-used across multiple applications.
Once attackers gain access, they may take advantage of privilege level to remove or alter data, take down a site or app, or hold any of the above for ransom. The risk across multiple similar projects is even greater. If code containing the credentials is reused across multiple projects, they will all be compromised.
Best practices for prevention
- Plan software architecture such that keys and passwords are always stored outside the code, wherever possible.
- Plan encryption into software architecture for all credential information and ensure proper handling of keys, credentials, and passwords.
- Prompt for a secure password on first login rather than hard-code a default password.
- If a hardcoded password or credential must be used, limit its use, for example, to system console users rather than via the network.
- Use strong hashes for inbound password authentication, ideally with randomly assigned salts to increase the difficulty level in case of brute-force attack.