Status-check approval spoofing via inherited merge-request permission
Published Feb 9, 2022 · Updated Aug 4, 2024
Incorrect authorization in GitLab EE allows remote authenticated users to spoof external status-check approval on a merge request. The API's find_merge_request_with_access check requests approve_merge_request, but policy inheritance grants that permission through update_merge_request to Guest authors and assignees. A personal access token and an Ultimate-tier project with an external status check are required; the forged approval can falsely mark an unchecked merge request as accepted.
Summary
What happened
Incorrect authorization in GitLab EE allows remote authenticated users to spoof external status-check approval on a merge request. The API's find_merge_request_with_access check requests approve_merge_request, but policy inheritance grants that permission through update_merge_request to Guest authors and assignees. A personal access token and an Ultimate-tier project with an external status check are required; the forged approval can falsely mark an unchecked merge request as accepted.
The record
- CVE
- CVE-2021-39943
- Published
- Feb 9, 2022
- Updated
- Aug 4, 2024
- Vendor
- GitLab
- Product
- GitLab
- Classifications
- CWE-863, T1565.001
- Attack vector
- network
- Privileges
- authenticated
Timeline
How it unfolded
- Feb 9, 2022CVE publishedPublication date reported by the CVE source.
- Aug 4, 2024Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=>=14.1.0, <14.3.6
- Affected versionversion=>=14.4.0, <14.4.4
- Affected versionversion=>=14.5.0, <14.5.2
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Public exploit references
- GitLab external status-check approval reproductionproof of concept · demonstrated
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Technologies
Your stack
See the directory against your own environment.
Your stack
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