An issue has been discovered in GitLab affecting all versions prior to 13.2.10, 13.3.7 and 13.4.2. Sessions keys are stored in plain-text in Redis which allows attacker with Redis access to authenticate as any user that has a session stored in Redis
https://gitlab.com/gitlab-org/gitlab/-/issues/17817
https://gitlab.com/gitlab-org/cves/-/blob/master/2020/CVE-2020-13344.json