CVE-2023-5106 Explained : Impact and Mitigation

An issue has been discovered in Ultimate-licensed GitLab EE affecting all versions starting 13.12 prior to 16.2.8, 16.3.0 prior to 16.3.5, and 16.4.0 prior to 16.4.1 that could allow an attacker to impersonate users in CI pipelines through direct transfer group imports.

Understanding CVE-2023-5106

This CVE relates to an improper access control vulnerability in GitLab that could potentially lead to attackers impersonating users in CI pipelines.

What is CVE-2023-5106?

The CVE-2023-5106 vulnerability in GitLab allows unauthorized access for attackers to impersonate users through direct transfer group imports, impacting the security and integrity of CI pipelines.

The Impact of CVE-2023-5106

With CVE-2023-5106, attackers could exploit the vulnerability to gain unauthorized access and impersonate users within CI pipelines, potentially leading to unauthorized actions and data breaches.

Technical Details of CVE-2023-5106

This section provides more in-depth technical insights into the vulnerability.

Vulnerability Description

The vulnerability, categorized as CWE-284: Improper Access Control, specifically affects GitLab versions 13.12 to 16.2.8, 16.3.0 to 16.3.5, and 16.4.0 to 16.4.1, enabling attackers to impersonate users through direct transfer group imports.

Affected Systems and Versions

The affected systems include all GitLab versions between 13.12 and 16.4.0. Users with versions prior to 16.2.8, 16.3.5, and 16.4.1 are at risk of this vulnerability.

Exploitation Mechanism

The vulnerability allows attackers to exploit the improper access control and impersonate users in CI pipelines through direct transfer group imports, potentially leading to unauthorized activities within the GitLab environment.

Mitigation and Prevention

To prevent exploitation and enhance the security of GitLab environments, specific mitigation steps and long-term security practices should be followed.

Immediate Steps to Take

Immediate upgrade to patched versions such as 16.2.8, 16.3.5, or 16.4.1 is recommended to eliminate the vulnerability.
Disable the "Migrate groups by direct transfer" feature until the upgrade to patched versions is completed.

Long-Term Security Practices

Regularly update GitLab to the latest versions to ensure security patches are applied promptly.
Educate users on secure practices and the importance of maintaining up-to-date software.

Patching and Updates

Regularly check for security updates and patches provided by GitLab and apply them promptly to mitigate the risk of exploitation.

Credit to GitLab team member Joern Schneeweisz for discovering this vulnerability internally.