CVE-2023-23763 : Security Advisory and Response

This CVE-2023-23763 was published on September 1, 2023, affecting GitHub Enterprise Server versions prior to 3.10.0. The vulnerability allowed a fork to retain read access to an upstream repository after its visibility was changed to private.

Understanding CVE-2023-23763

This CVE involves an authorization/sensitive information disclosure vulnerability in GitHub Enterprise Server.

What is CVE-2023-23763?

The vulnerability in GitHub Enterprise Server allowed a fork to maintain read access to an upstream repository even after the repository's visibility was changed to private. This issue impacted versions of GitHub Enterprise Server before 3.10.0.

The Impact of CVE-2023-23763

The impact of this vulnerability is categorized under CAPEC-116 Excavation. It could potentially lead to the exposure of sensitive information to unauthorized actors.

Technical Details of CVE-2023-23763

This section delves into the specifics of the vulnerability.

Vulnerability Description

The vulnerability in GitHub Enterprise Server permitted forks to continue accessing an upstream repository despite its visibility being set to private.

Affected Systems and Versions

GitHub Enterprise Server versions 3.6.0, 3.7.0, 3.8.0, and 3.9.0 were affected by this issue, with fixes made available in versions 3.6.18, 3.7.16, 3.8.9, and 3.9.4.

Exploitation Mechanism

The exploitation of this vulnerability could allow unauthorized access to sensitive information in private repositories within GitHub Enterprise Server.

Mitigation and Prevention

Taking steps to mitigate and prevent the exploitation of this vulnerability is crucial for maintaining security.

Immediate Steps to Take

Users of GitHub Enterprise Server should update to the fixed versions (3.6.18, 3.7.16, 3.8.9, 3.9.4) to address the vulnerability and prevent unauthorized access.

Long-Term Security Practices

Implementing strict access controls, monitoring access to repositories, and regularly updating software are essential long-term security practices to prevent similar vulnerabilities.

Patching and Updates

Regularly monitoring security updates and promptly applying patches provided by GitHub for GitHub Enterprise Server is essential to ensure the security and integrity of the platform.