ClaimApplication · Jenkins
CVE-2021-21619
Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.
NVD · uneditedJenkins Claim Plugin 2.18.1 and earlier does not escape the user display name, resulting in a stored cross-site scripting (XSS) vulnerability exploitable by attackers who are able to control the display names of Jenkins users, either via the security realm, or directly inside Jenkins.
Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.
dbcve analysis · high confidenceThe Jenkins Claim Plugin fails to escape user display names before rendering them in the web interface, creating a stored XSS vulnerability. Attackers with control over Jenkins user display names (via security realm or direct user management) can inject malicious scripts that execute in other users' browsers when they view affected pages.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.
NVD · CPE data
ClaimApplication
<= 2.18.1CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.
From the vector- Attack vector
- Network
- Complexity
- Low
- Privileges
- Low
- User interaction
- Required
- Scope
- Changed
- Confidentiality
- Low
- Integrity
- Low
- Availability
- None
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N
Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.
dbcve checksWork through these to decide whether this CVE applies to you.
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Check installed Claim Plugin versionNavigate to Manage Jenkins > Manage Plugins > Installed tab, locate 'Claim Plugin' in the list, and note the version number displayed in the Version columnAffected if The installed version is 2.18.1 or lower
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Verify Claim plugin is activeOn the Manage Plugins page, ensure the Claim Plugin shows as 'Enabled' or 'Active' in the status columnAffected if The plugin is enabled and the version is 2.18.1 or lower
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Confirm Claim plugin usage in jobs or viewsReview Jenkins jobs or views that use the Claim plugin feature (check job configurations for 'Enable Claim' checkbox or 'Claim' build step)Affected if The plugin is in use and the version is 2.18.1 or lower
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Identify users with elevated display name controlCheck Jenkins user directories or security realms (such as LDAP, Active Directory, or Jenkins own user database) for users who can modify their display namesAffected if Users can control their display names and the Claim plugin version is 2.18.1 or lower
If the Claim Plugin version is 2.18.1 or earlier and the plugin is enabled with claim functionality in use, the environment is affected by this stored XSS vulnerability.
Generated from the published advisory. Verify against your own configuration.
Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.
From vendor dataUpgrade Jenkins Claim Plugin to version 2.18.2 or later, which implements proper HTML encoding of user display names.
Fix this in Claim
Scoped from the published advisory
- Consultation4.0 h
- Implementation2.0 h
- Testing4.0 h
- Review / QA2.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $3,392.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2021-21619 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2021-21619 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.
- Verified mitigations, workarounds, and config changes
- Version or environment caveats, and links to real fixes
- No weaponised exploit code, or anything meant to cause harm
- No spam, self-promotion, credentials, or personal data