CVE-2020-13270 — Missing permission check on fork relation creation in GitLab CE/EE 11

Missing permission check on fork relation creation in GitLab CE/EE 11.3 and later through 13.0.1 allows guest users to create a fork relation on restricted public projects via API

01What is this vulnerability?

Missing permission check on fork relation creation in GitLab CE/EE 11.3 and later through 13.0.1 allows guest users to create a fork relation on restricted public projects via API

02Affected products

Vendor	Product	Versions
GitLab	GitLab	>=11.3, <12.9.8, >=12.10, <12.10.7, >=13.0, <13.0.1

03Active exploitation status

Not currently listed on the CISA Known Exploited Vulnerabilities (KEV) catalog. EPSS is the best forward-looking signal — see the EPSS row above.

04Recommended remediation

• Patch to a fixed version listed in the vendor advisory (see references below).
• Mitigate with WAF rules, network egress filters, or feature flags where the patch is not yet available.
• Hunt historical logs for exploitation indicators — see Detection signatures below.

05Technical details

For the full vendor write-up, exploit chains, and reference implementations, see the references list in section 09.

06Detection signatures

Ask SARA in chat to draft a starting detection for this CVE in your stack of choice.

07Related CVEs

No directly-cited follow-up CVEs in the KB record for this advisory. The references list in section 09 carries the vendor cross-references.

08Timeline

• Published: 2020-06-10T14:35:07.000Z
• Last modified: 2024-08-04T12:11:19.468Z

09References

• gitlab.com — https://gitlab.com/gitlab-org/gitlab/-/issues/24648
• hackerone.com — https://hackerone.com/reports/419977
• gitlab.com — https://gitlab.com/gitlab-org/cves/-/blob/master/2020/CVE-2020-13270.json