Improper access control in the GitLab CE/EE API affecting all versions starting from 9.4 before 14.3.6, all versions starting from 14.4 before 14.4.4, all versions starting from 14.5 before 14.5.2, allows an author of a Merge Request to approve the Merge Request even after having their project access revoked
CWE-863 - Incorrect Authorization
Authorization is a security mechanism performed by an application to grant or deny access to the requested resources by verifying the privileges of the user. When an application lacks effective authorization mechanisms, it enables unauthorized users to gain unintended privileges and illegitimate access to resources. Such a vulnerability may result in exposure of sensitive information, denial of service, arbitrary code execution, and complete system takeover.