🛡️ CVE-2021-21684 — git
Description
Stored XSS vulnerability in Jenkins Git Plugin
Jenkins Git Plugin 4.8.2 and earlier does not escape the Git SHA-1 checksum parameters provided to commit notifications when displaying them in a build cause.
This results in a stored cross-site scripting (XSS) vulnerability exploitable by attackers able to submit crafted commit notifications to the /git/notifyCommit endpoint.
Jenkins Git Plugin 4.8.3 rejects Git SHA-1 checksum parameters that do not match the expected format. Existing values are sanitized when displayed on the UI.
This vulnerability is only exploitable in Jenkins 2.314 and earlier, LTS 2.303.1 and earlier. See the [LTS upgrade guide](https://www.jenkins.io/doc/upgrade-guide/2.303/#SECURITY-2452).
How this vulnerability can be exploited
This issue can be reached over the network, attack complexity is low, an attacker needs no privileges on the target. A user must be tricked into taking some action. The scope is changed, meaning a successful attack can affect components beyond the vulnerable one. Rated impact: confidentiality low, integrity low, availability none.
Weakness class
CVE-2021-21684 is classified as CWE-116: Improper Encoding or Escaping of Output. Output is emitted without encoding it for the context it lands in, so data is interpreted as markup or code.
Affected software
CVE-2021-21684 is recorded against 1 package.
- org.jenkins-ci.plugins:git (fixed in 4.8.3)
Timeline and source
Published on 24 May 2022 and last revised on 16 February 2024. No public exploit is currently recorded for this entry. Record sourced from OSV.
References
nvd.nist.gov (Advisory)
github.com (Web)
github.com (Package)
www.jenkins.io (Web)
www.openwall.com (Web)
Details
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
Affected Packages
| Software | From version | Fixed in |
|---|---|---|
| org.jenkins-ci.plugins:git | — | 4.8.3 |
References
Similar Threats
- Critical CVE-2026-42523
- Medium CVE-2025-67640
- Medium CVE-2025-58458
- Medium CVE-2024-34146
- High CVE-2024-23899
More CVE 2021 advisories
Browse all of CVE 2021 in the advisory index.
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