CVE-2021-22868 : Security Advisory and Response

A path traversal vulnerability was identified in GitHub Enterprise Server that could be exploited when building a GitHub Pages site.

Understanding CVE-2021-22868

This CVE describes a path traversal vulnerability in GitHub Enterprise Server that was reported via the GitHub Bug Bounty program.

What is CVE-2021-22868?

A path traversal vulnerability in GitHub Enterprise Server allowed attackers, with permission to build a GitHub Pages site, to read files on the server. The vulnerability affected versions prior to 3.1.8 and was fixed in versions 3.1.8, 3.0.16, and 2.22.22.

The Impact of CVE-2021-22868

This vulnerability could be exploited by attackers to access sensitive information on the GitHub Enterprise Server, compromising data integrity and security.

Technical Details of CVE-2021-22868

The vulnerability stems from unsafe configuration options in GitHub Pages that were not properly restricted, enabling the path traversal attack.

Vulnerability Description

Insufficient restrictions on user-controlled configuration options for GitHub Pages allowed unauthorized access to server files.

Affected Systems and Versions

GitHub Enterprise Server versions prior to 3.1.8
Versions fixed: 3.1.8, 3.0.16, and 2.22.22

Exploitation Mechanism

Attackers required permission to create and build a GitHub Pages site on the server to exploit this path traversal vulnerability.

Mitigation and Prevention

It is crucial to take immediate steps to address this vulnerability and implement long-term security measures to prevent future exploits.

Immediate Steps to Take

Update GitHub Enterprise Server to versions 3.1.8, 3.0.16, or 2.22.22 to patch the vulnerability.
Review access permissions to restrict building GitHub Pages sites.

Long-Term Security Practices

Regularly update and patch GitHub Enterprise Server to mitigate known vulnerabilities.
Conduct security assessments to identify and address potential security risks.

Patching and Updates

Stay informed about security updates from GitHub and promptly apply patches to secure the server against emerging threats.