A vulnerability was discovered in GitLab versions before 13.1.10, 13.2.8 and 13.3.4. GitLab Webhook feature could be abused to perform denial of service attacks due to the lack of rate limitation.
https://hackerone.com/reports/904134
https://gitlab.com/gitlab-org/gitlab/-/issues/223681
https://gitlab.com/gitlab-org/cves/-/blob/master/2020/CVE-2020-13306.json