CVE-2021-39889 : Exploit Details and Defense Strategies

In this article, we will provide detailed information about CVE-2021-39889, a vulnerability in GitLab.

Understanding CVE-2021-39889

CVE-2021-39889 is a security vulnerability found in GitLab affecting multiple versions.

What is CVE-2021-39889?

In all versions of GitLab EE since version 14.1, there is an insecure direct object reference vulnerability that exposes the protected branch name to a malicious user through a crafted API call.

The Impact of CVE-2021-39889

The impact of this vulnerability is rated as medium with a base score of 4.3. It can lead to confidentiality issues due to the exposure of protected branch names.

Technical Details of CVE-2021-39889

This section provides in-depth technical details of the vulnerability.

Vulnerability Description

The vulnerability in GitLab allows a malicious user to retrieve the protected branch name via an insecure API call.

Affected Systems and Versions

GitLab versions >=14.1, <14.1.7
GitLab versions >=14.2, <14.2.5
GitLab versions >=14.3, <14.3.1

Exploitation Mechanism

The vulnerability can be exploited by crafting API calls to reveal protected branch names.

Mitigation and Prevention

Learn how to protect your systems from CVE-2021-39889.

Immediate Steps to Take

Update GitLab to version 14.1.7, 14.2.5, or 14.3.1
Monitor and restrict API access for sensitive endpoints

Long-Term Security Practices

Conduct regular security audits and code reviews
Educate users on secure API usage

Patching and Updates

Stay informed about security patches and updates provided by GitLab