Fix for CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')

[asadeddin]

Corgea is an AI security engineer that fixes vulnerable code.

It issued this PR to fix a vulnerability for you to review.

See the issue and fix in Corgea.

Explanation of the issue

CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
The product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users.

Cross-site scripting (XSS) vulnerabilities occur when:

Untrusted data enters a web application, typically from a web request.
The web application dynamically generates a web page that contains this untrusted data.
During page generation, the application does not prevent the data from containing content that is executable by a web browser, such as JavaScript, HTML tags, HTML attributes, mouse events, Flash, ActiveX, etc.
A victim visits the generated web page through a web browser, which contains malicious script that was injected using the untrusted data.
Since the script comes from a web page that was sent by the web server, the victim's web browser executes the malicious script in the context of the web server's domain.
This effectively violates the intention of the web browser's same-origin policy, which states that scripts in one domain should not be able to access resources or run code in a different domain.

Explanation of the fix

The security fix addresses a Cross-Site Scripting (XSS) vulnerability by correctly neutralizing user-controllable input before it is placed in output that is used as a web page.

• The vulnerability was due to the use of f-string formatting in Python, which doesn't automatically escape HTML special characters, potentially leading to XSS attacks.
• The fix replaces f-string formatting with the format_html function, which safely formats HTML strings by escaping any potentially harmful characters.
• This change ensures that any user-controllable input, specifically config.plugin.name and config.plugin_id, is correctly neutralized before being served to other users in a web page.
• The fix is applied in the plugin_name method of the PluginConfigAdmin class in the posthog/admin.py file.
• This fix is crucial to prevent attackers from injecting malicious scripts into the web page, which could lead to data theft, unauthorized actions, or even taking over the victim's machine.