CVE-2021-39911 Explained : Impact and Mitigation

This CVE article provides details about an improper access control vulnerability affecting GitLab versions.

Understanding CVE-2021-39911

This section explains the vulnerability, its impact, affected systems, and mitigation steps.

What is CVE-2021-39911?

An improper access control flaw in GitLab versions exposes private email addresses of Issue and Merge Requests assignees to Webhook data consumers.

The Impact of CVE-2021-39911

The vulnerability has a CVSS base score of 1.7 (Low severity) with High Attack Complexity and Physical Attack Vector.

Technical Details of CVE-2021-39911

This section dives into the vulnerability description, affected systems, and exploitation mechanism.

Vulnerability Description

The flaw allows unauthorized access to private email addresses via GitLab's Issue and Merge Requests.

Affected Systems and Versions

GitLab versions >=13.9 and <14.2.6
GitLab versions >=14.3 and <14.3.4
GitLab versions >=14.4 and <14.4.1

Exploitation Mechanism

Attack Complexity: HIGH
Attack Vector: PHYSICAL
Privileges Required: LOW
User Interaction: REQUIRED
Confidentiality Impact: LOW

Mitigation and Prevention

This section provides guidance on immediate steps and long-term security practices.

Immediate Steps to Take

Update GitLab to versions 14.2.6, 14.3.4, or 14.4.1 to patch the vulnerability.
Review and secure sensitive email data stored in GitLab.

Long-Term Security Practices

Regularly monitor and audit access controls in GitLab.
Train users on data protection best practices.

Patching and Updates

GitLab has released patches in versions 14.2.6, 14.3.4, and 14.4.1.