An issue has been discovered in GitLab CE/EE affecting all versions starting from 8.14. A path traversal is found in LFS Upload that allows attacker to overwrite certain specific paths on the server. Affected versions are: >=8.14, <13.3.9,>=13.4, <13.4.5,>=13.5, <13.5.2.
https://hackerone.com/reports/990800
https://gitlab.com/gitlab-org/gitlab/-/issues/255886
https://gitlab.com/gitlab-org/cves/-/blob/master/2020/CVE-2020-13355.json