CVE-2021-22238 : Security Advisory and Response

An issue has been discovered in GitLab affecting all versions starting with 13.3. This vulnerability allows for stored cross-site scripting (XSS) attacks by exploiting the design feature in GitLab's issues.

Understanding CVE-2021-22238

This CVE details a stored XSS vulnerability in GitLab, impacting versions 13.3 and above. The vulnerability was reported by vakzz through the HackerOne bug bounty program.

What is CVE-2021-22238?

CVE-2021-22238 is a security flaw in GitLab that enables attackers to execute malicious scripts in the context of an authenticated user on the affected GitLab instance.

The Impact of CVE-2021-22238

The vulnerability could result in unauthorized access to sensitive data, manipulation of content, and potentially lead to account takeover or other serious security breaches on GitLab instances.

Technical Details of CVE-2021-22238

GitLab versions >=14.1, <14.1.2, >=14.0, <14.0.7, and >13.3, <13.12.9 are affected by this stored XSS vulnerability.

Vulnerability Description

The vulnerability arises from improper neutralization of input during web page generation, allowing for cross-site scripting attacks within GitLab's issue design functionality.

Affected Systems and Versions

All GitLab versions from 13.3 onwards are affected, including versions >=14.1, <14.1.2, >=14.0, <14.0.7, and >13.3, <13.12.9.

Exploitation Mechanism

Attackers can exploit this vulnerability by injecting and executing malicious scripts when designing issues in GitLab, potentially leading to unauthorized actions.

Mitigation and Prevention

It is crucial to take immediate action to mitigate the risks associated with CVE-2021-22238.

Immediate Steps to Take

Update GitLab to versions 14.1.2, 14.0.7, or 13.12.9 to address the vulnerability.
Regularly monitor for any unusual activities on GitLab instances.
Educate users on recognizing and avoiding malicious scripts.

Long-Term Security Practices

Implement content security policies (CSP) to mitigate XSS attacks.
Conduct regular security audits and penetration testing on GitLab instances.

Patching and Updates

Stay informed about security patches and updates released by GitLab to address known vulnerabilities and protect your GitLab environment.