CVE-2021-39930 : What You Need to Know

This CVE-2021-39930 article provides details about a vulnerability in GitLab versions 12.4 to 14.5.2, allowing unauthorized access to user templates.

Understanding CVE-2021-39930

CVE-2021-39930 is a security vulnerability in GitLab versions 12.4 to 14.5.2 that enables attackers to access user templates without proper authorization.

What is CVE-2021-39930?

The vulnerability in GitLab versions 12.4 to 14.5.2 allows attackers to reach a user's custom project and group templates due to missing authorization controls.

The Impact of CVE-2021-39930

The impact of this CVE is rated with a CVSS v3.1 base score of 4.3 (Medium severity) due to low complexity and privilege requirements for exploitation.

Technical Details of CVE-2021-39930

This section delves into the specific technical aspects of the CVE.

Vulnerability Description

The vulnerability enables unauthorized users to access custom project and group templates in GitLab versions 12.4 through 14.5.2.

Affected Systems and Versions

Affected Product: GitLab
Vulnerable Versions:
Versions >=12.4 and <14.3.6
Versions >=14.4 and <14.4.4
Versions >=14.5 and <14.5.2

Exploitation Mechanism

The vulnerability can be exploited through direct requests ('forced browsing') in GitLab, bypassing authorization checks.

Mitigation and Prevention

In this section, we outline steps to mitigate the CVE-2021-39930 vulnerability.

Immediate Steps to Take

Update GitLab to versions 14.3.6, 14.4.4, or 14.5.2 to patch the vulnerability.
Monitor user activities related to project and group templates for any suspicious behavior.

Long-Term Security Practices

Implement proper access controls and authorization mechanisms in GitLab to prevent unauthorized template access.
Regularly review and update security configurations to address similar vulnerabilities in the future.

Patching and Updates

Keep GitLab systems up to date with the latest security patches and version releases to prevent known vulnerabilities.