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Stored XSS at user email

Moderate
thorsten published GHSA-q7g6-xfh2-vhpx Mar 25, 2024

Package

No package listed

Affected versions

3.2.5

Patched versions

3.2.6

Description

Summary

The email field in phpMyFAQ's user control panel page is vulnerable to stored XSS attacks due to the inadequacy of PHP's FILTER_VALIDATE_EMAIL function, which only validates the email format, not its content. This vulnerability enables an attacker to execute arbitrary client-side JavaScript within the context of another user's phpMyFAQ session.

Details

Despite using PHP's FILTER_VALIDATE_EMAIL function, the email field does not adequately validate the content of the email address. This means that malicious input, such as JavaScript code, can be accepted and stored in the database without being detected. When the stored data is retrieved and displayed on web pages, it is not properly sanitized to remove or neutralize any potentially harmful content, such as JavaScript code which leads to Stored XSS.

PoC

  1. Login as any user, go to the user control panel, change email to any valid email and intercept the request.

  2. Modify the request’s email parameter to the following payload: "><svg/onload=confirm('XSS')>"@x.y
    image

  3. Send the request and see that the XSS is triggered in the user control panel page.
    image

  4. Also affects any user who browse to "../admin/?action=user&user_action=listallusers"
    image

Impact

This allows an attacker to execute arbitrary client side JavaScript within the context of another user's phpMyFAQ session.

Severity

Moderate

CVSS overall score

This score calculates overall vulnerability severity from 0 to 10 and is based on the Common Vulnerability Scoring System (CVSS).
/ 10

CVSS v3 base metrics

Attack vector
Network
Attack complexity
Low
Privileges required
Low
User interaction
Required
Scope
Unchanged
Confidentiality
Low
Integrity
Low
Availability
Low

CVSS v3 base metrics

Attack vector: More severe the more the remote (logically and physically) an attacker can be in order to exploit the vulnerability.
Attack complexity: More severe for the least complex attacks.
Privileges required: More severe if no privileges are required.
User interaction: More severe when no user interaction is required.
Scope: More severe when a scope change occurs, e.g. one vulnerable component impacts resources in components beyond its security scope.
Confidentiality: More severe when loss of data confidentiality is highest, measuring the level of data access available to an unauthorized user.
Integrity: More severe when loss of data integrity is the highest, measuring the consequence of data modification possible by an unauthorized user.
Availability: More severe when the loss of impacted component availability is highest.
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:L/I:L/A:L

CVE ID

CVE-2024-27300

Weaknesses

Credits