CVE-2020-13346 Explained : Impact and Mitigation

Membership changes not reflected in ToDo subscriptions in GitLab versions prior to 13.2.10, 13.3.7, and 13.4.2, allowing unauthorized access to confidential issues.

Understanding CVE-2020-13346

This CVE involves an improper access control issue in GitLab versions that could potentially lead to unauthorized access to sensitive information.

What is CVE-2020-13346?

This vulnerability in GitLab versions before 13.2.10, 13.3.7, and 13.4.2 allows guest users to access confidential issues through the API due to a lack of proper reflection of membership changes in ToDo subscriptions.

The Impact of CVE-2020-13346

The vulnerability poses a medium severity risk with a CVSS base score of 6.5, impacting confidentiality by allowing unauthorized access to confidential issues.

Technical Details of CVE-2020-13346

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

Vulnerability Description

The issue arises from the failure to update ToDo subscriptions with membership changes, enabling guest users to exploit the API for unauthorized access.

Affected Systems and Versions

Affected Versions: GitLab >=11.2, <13.2.10, >=13.3.0, <13.3.7, >=13.4.0, <13.4.2

Exploitation Mechanism

Unauthorized users can leverage the lack of proper reflection of membership changes in ToDo subscriptions to access confidential issues through the API.

Mitigation and Prevention

Protect your systems from CVE-2020-13346 with the following steps:

Immediate Steps to Take

Upgrade GitLab to versions 13.2.10, 13.3.7, or 13.4.2 to mitigate the vulnerability.
Monitor and restrict API access to prevent unauthorized usage.

Long-Term Security Practices

Regularly review and update access controls to ensure proper authorization.
Conduct security training to educate users on best practices for handling sensitive information.

Patching and Updates

Stay informed about security patches and updates released by GitLab to address vulnerabilities promptly.