CVE-2021-39933 : Security Advisory and Response

CVE-2021-39933 is a vulnerability affecting GitLab versions that could lead to a Denial of Service (DoS) attack.

Understanding CVE-2021-39933

This section provides insights into the nature and impact of the CVE-2021-39933 vulnerability.

What is CVE-2021-39933?

CVE-2021-39933 is an issue in GitLab CE/EE versions, allowing for a DoS attack due to catastrophic backtracking in regular expression usage.

The Impact of CVE-2021-39933

The vulnerability has a CVSS base score of 4.3 (Medium severity) and affects the availability of the systems running the impacted GitLab versions.

Technical Details of CVE-2021-39933

Here, you will find in-depth technical details about the CVE-2021-39933 vulnerability.

Vulnerability Description

The vulnerability arises from a regular expression used in GitLab to handle user input, leading to potential DoS attacks.

Affected Systems and Versions

GitLab versions >=12.10, <14.3.6
GitLab versions >=14.4, <14.4.4
GitLab versions >=14.5, <14.5.2

Exploitation Mechanism

The vulnerability allows attackers to exploit the regular expression to cause a DoS situation by inducing catastrophic backtracking.

Mitigation and Prevention

Learn how to protect your systems from the CVE-2021-39933 vulnerability.

Immediate Steps to Take

Update GitLab to versions 14.3.6, 14.4.4, or 14.5.2 to mitigate the vulnerability.
Monitor system resources for any unusual activity that might indicate a DoS attack.
Implement rate limiting to prevent potential DoS attacks.

Long-Term Security Practices

Regularly update and patch GitLab to the latest versions to avoid known vulnerabilities.
Conduct security audits and testing to identify and address any potential weaknesses.
Educate users about secure input handling practices to minimize the risk of DoS attacks.

Patching and Updates

Stay informed about security advisories from GitLab and promptly apply relevant patches.