CVE-2023-0838 — An issue has been discovered in GitLab affecting versions starting from 15

An issue has been discovered in GitLab affecting versions starting from 15.1 before 15.8.5, 15.9 before 15.9.4, and 15.10 before 15.10.1. A maintainer could modify a webhook URL to leak masked webhook secrets by adding a new parameter to the url. This addresses an incomplete fix

01What is this vulnerability?

An issue has been discovered in GitLab affecting versions starting from 15.1 before 15.8.5, 15.9 before 15.9.4, and 15.10 before 15.10.1. A maintainer could modify a webhook URL to leak masked webhook secrets by adding a new parameter to the url. This addresses an incomplete fix for CVE-2022-4342.

02Affected products

Vendor	Product	Versions
GitLab	GitLab	>=15.1, <15.8.5, >=15.9, <15.9.4, >=15.10, <15.10.1

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

08Timeline

• Published: 2023-04-05T00:00:00.000Z
• Last modified: 2025-02-10T20:59:42.972Z

09References

• gitlab.com — https://gitlab.com/gitlab-org/gitlab/-/issues/391685
• hackerone.com — https://hackerone.com/reports/1871136
• gitlab.com — https://gitlab.com/gitlab-org/cves/-/blob/master/2023/CVE-2023-0838.json