CVE-2023-23764 : Exploit Details and Defense Strategies

This CVE-2023-23764 pertains to an incorrect comparison vulnerability found in GitHub Enterprise Server that could potentially lead to commit smuggling. The vulnerability was published on July 27, 2023.

Understanding CVE-2023-23764

This section provides an overview of the nature of the vulnerability and its impact.

What is CVE-2023-23764?

The vulnerability identified in GitHub Enterprise Server allowed commit smuggling by displaying an incorrect diff within the GitHub pull request UI. To exploit this vulnerability, an attacker would require write access to the affected repository.

The Impact of CVE-2023-23764

The vulnerability has been classified under CWE-697, with a CVSS base score of 4.8, indicating a medium severity issue. It has a high integrity impact, low confidentiality impact, requires high privileges, and user interaction is required for exploitation. The attack complexity is considered high, with the attack vector being network-based.

Technical Details of CVE-2023-23764

This section delves into the specifics of the vulnerability, including its description, affected systems and versions, as well as the exploitation mechanism.

Vulnerability Description

The vulnerability arose due to an incorrect comparison within the GitHub Enterprise Server, leading to the potential for commit smuggling through the display of an incorrect diff in the pull request UI.

Affected Systems and Versions

GitHub Enterprise Server versions 3.7.0 and above were affected by this vulnerability. The issue was resolved in versions 3.7.9, 3.8.2, and 3.9.1 of the GitHub Enterprise Server.

Exploitation Mechanism

To exploit this vulnerability, an attacker needed write access to the repository to manipulate the incorrect diff displayed within the GitHub pull request UI.

Mitigation and Prevention

In this section, we discuss the steps that can be taken to mitigate the risks posed by CVE-2023-23764.

Immediate Steps to Take

It is recommended to update the GitHub Enterprise Server to versions 3.7.9, 3.8.2, or 3.9.1 to address and mitigate the vulnerability. Additionally, users should review and monitor access controls to repositories to prevent unauthorized write access that could be exploited by attackers.

Long-Term Security Practices

In the long term, organizations should regularly update their systems and software to the latest versions to ensure that known vulnerabilities are patched. Employing strong access control mechanisms and regularly monitoring for any unauthorized activity can also help in enhancing overall security posture.

Patching and Updates

GitHub has released patches for the affected versions (3.7.9, 3.8.2, and 3.9.1) to address the vulnerability. Organizations are advised to promptly apply these patches to secure their GitHub Enterprise Server installations.