CVE-2021-39898 : Security Advisory and Response

CVE-2021-39898 affects GitLab versions from 10.6 to 14.3.1, potentially leaking sensitive information through project exports.

Understanding CVE-2021-39898

This CVE involves information exposure in GitLab, impacting the integrity of project data due to a vulnerability in project exports.

What is CVE-2021-39898?

In GitLab versions since 10.6, a project export flaw exposes the external webhook token, leading to potential unauthorized access to the project.

The Impact of CVE-2021-39898

CVSS Score: 3.7 (Low severity)
Attack Complexity: High
Attack Vector: Network
Confidentiality Impact: Low

Technical Details of CVE-2021-39898

This section provides specific technical details of the vulnerability.

Vulnerability Description

The vulnerability in GitLab allows the external webhook token value to be leaked during project exports, compromising project security.

Affected Systems and Versions

GitLab versions >=10.6 and <14.1.7
GitLab versions >=14.2 and <14.2.5
GitLab versions >=14.3 and <14.3.1

Exploitation Mechanism

Attackers can exploit this vulnerability by intercepting and misusing the exposed external webhook token to gain unauthorized access.

Mitigation and Prevention

To secure GitLab instances from CVE-2021-39898, follow these mitigation strategies:

Immediate Steps to Take

Upgrade affected GitLab instances to versions beyond 14.3.1
Monitor project exports for suspicious activities

Long-Term Security Practices

Implement strict access control policies for project exports
Regularly review and update webhook configurations

Patching and Updates

GitLab has released fixes for this issue in versions post-14.3.1. Ensure timely installation of patches and updates.