CVE-2021-39885 : What You Need to Know

A Stored XSS vulnerability in GitLab versions allowing execution of arbitrary JavaScript code.

Understanding CVE-2021-39885

This CVE involves a Stored XSS vulnerability in GitLab versions that enables malicious code execution.

What is CVE-2021-39885?

A Stored XSS vulnerability in GitLab versions >=13.7, <14.1.7, >=14.2, <14.2.5, and >=14.3, <14.3.1.
Reported by joaxcar through GitLab's HackerOne bug bounty program.

The Impact of CVE-2021-39885

CVSS Score: 8.7 (High Severity)
Impact: High confidentiality and integrity impact, low privileges required, user interaction required.

Technical Details of CVE-2021-39885

GitLab's vulnerability specifics and affected systems.

Vulnerability Description

Vulnerability in the merge request creation page allowing arbitrary code execution.

Affected Systems and Versions

Affected versions include:
GitLab >=13.7, <14.1.7
GitLab >=14.2, <14.2.5
GitLab >=14.3, <14.3.1

Exploitation Mechanism

Attack vector: Network
Attack complexity: Low
Privileges required: Low
User interaction: Required

Mitigation and Prevention

Steps to secure systems and prevent exploitation.

Immediate Steps to Take

Update affected GitLab versions to the patched releases.
Monitor for any suspicious activities or code injections.

Long-Term Security Practices

Regular security audits and code reviews within the organization.
Educate users on security best practices and recognizing phishing attempts.

Patching and Updates

GitLab has released patches for the affected versions to fix the vulnerability.