CVE-2021-39903 : Security Advisory and Response

In this CVE-2021-39903 article, learn about a vulnerability in GitLab versions 13.0 to 14.4.1 that allows a privileged user to modify the visibility of a group or project despite restrictions set by the administrator.

Understanding CVE-2021-39903

CVE-2021-39903 is a security vulnerability that impacts GitLab versions 13.0 to 14.4.1, enabling unauthorized visibility changes by privileged users.

What is CVE-2021-39903?

This vulnerability in GitLab allows a privileged user to alter the visibility level of a group or project to a restricted option through API calls.

The Impact of CVE-2021-39903

The vulnerability poses a medium severity risk, with high confidentiality and integrity impact, making it crucial to address to prevent unauthorized changes.

Technical Details of CVE-2021-39903

Explore the technical aspects of the CVE-2021-39903 vulnerability in GitLab.

Vulnerability Description

Type: Improper authorization in GitLab
Description: A privileged user can modify visibility levels despite administrator restrictions.

Affected Systems and Versions

The following GitLab versions are affected:

GitLab >=13.0, <14.2.6
GitLab >=14.3, <14.3.4
GitLab >=14.4, <14.4.1

Exploitation Mechanism

The vulnerability can be exploited by a privileged user through API calls to change visibility options.

Mitigation and Prevention

Discover the steps to mitigate and prevent the CVE-2021-39903 vulnerability.

Immediate Steps to Take

Update GitLab to version 14.2.6, 14.3.4, or 14.4.1 to patch the vulnerability.
Monitor visibility changes in groups and projects for unexpected modifications.

Long-Term Security Practices

Implement a least privilege principle to restrict user capabilities.
Regularly review and update visibility settings and access controls within GitLab.

Patching and Updates

Apply security patches provided by GitLab promptly to address vulnerabilities.