An authorization issue in the mirroring logic allowed read access to private repositories in GitLab CE/EE 10.6 and later through 13.0.5
https://hackerone.com/reports/894569
https://gitlab.com/gitlab-org/gitlab/-/issues/220972
https://gitlab.com/gitlab-org/cves/-/blob/master/2020/CVE-2020-13277.json