CVE-2021-39903
Description
In all versions of GitLab CE/EE since version 13.0, a privileged user, through an API call, can change the visibility level of a group or a project to a restricted option even after the instance administrator sets that visibility option as restricted in settings.
Summary dbcve.org
In GitLab CE/EE versions 13.0 and later, the API endpoint for changing group or project visibility does not properly enforce administrator-configured visibility restrictions. A privileged user can bypass these restrictions via API calls to set visibility to restricted options that the instance administrator has explicitly disabled.
Mitigation
Upgrade GitLab to the patched version. As a compensating control, monitor API access logs for unauthorized visibility change attempts and consider restricting API token permissions for privileged users.