CVE-2021-39938 : Security Advisory and Response

This CVE-2021-39938 article provides detailed information about a vulnerability found in GitLab versions leading to Denial of Service due to uncontrolled resource consumption through specially crafted commands.

Understanding CVE-2021-39938

The CVE-2021-39938 vulnerability in GitLab affects versions of GitLab, potentially allowing attackers to exploit the system.

What is CVE-2021-39938?

A vulnerable regular expression pattern in GitLab versions allows attackers to cause uncontrolled resource consumption, leading to Denial of Service.

The Impact of CVE-2021-39938

CVSS Score: 3.1 (Low Severity)
Attack Complexity: High
Attack Vector: Network
Availability Impact: Low
This vulnerability could potentially lead to a Denial of Service attack.

Technical Details of CVE-2021-39938

Understanding the technical aspects of the CVE-2021-39938 vulnerability in GitLab.

Vulnerability Description

The vulnerability allows attackers to exploit GitLab instances by crafting specific commands to cause uncontrolled resource consumption.

Affected Systems and Versions

Affected Product: GitLab
Affected Versions:
GitLab >=14.5, <14.5.2
GitLab >=14.4, <14.4.4
GitLab >=8.15, <14.3.6
All versions from 8.15 before 14.3.6, and versions starting from 14.4 before 14.4.4 and 14.5 before 14.5.2.

Exploitation Mechanism

The vulnerability can be exploited by executing specially crafted deploy Slash commands, causing uncontrolled resource consumption.

Mitigation and Prevention

Guidelines on how to mitigate and prevent exploitation of CVE-2021-39938.

Immediate Steps to Take

Update GitLab to versions that contain patches for the vulnerability.
Monitor system resources for unusual activity.
Disable any unnecessary GitLab features.

Long-Term Security Practices

Regularly update GitLab to the latest versions.
Implement network security measures to detect and prevent unusual behavior.

Patching and Updates

Apply security patches provided by GitLab promptly.