Rest List ParameterApplication · Jenkins
CVE-2021-21635
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 REST List Parameter Plugin 1.3.0 and earlier does not escape a parameter name reference in embedded JavaScript, resulting in a stored cross-site scripting (XSS) vulnerability exploitable by attackers with Job/Configure permission.
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 REST List Parameter Plugin versions 1.3.0 and earlier contains a stored XSS vulnerability where parameter name references are not escaped before being embedded in JavaScript code, allowing injection of malicious scripts through the parameter name field.
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
Rest List ParameterApplication
<= 1.3.0CVSS 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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Verify REST List Parameter Plugin is installedNavigate to Manage Jenkins > Manage Plugins > Installed, or check $JENKINS_HOME/plugins/ for rest-list-parameter directory and its manifest (manifest.json or MANIFEST.MF)Affected if Plugin is present and version is 1.3.0 or earlier based on the plugin manifest
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Identify jobs using REST List ParameterSearch job configurations for '<restListParameter>' or 'RestListParameter' XML elements in $JENKINS_HOME/jobs/*/config.xml files, or use Jenkins script console: Jenkins.instance.allItems.collect { it.class.getResource('RestListParameterDefinition') ? it.name : null }.flatten().findAll { it }'Affected if One or more jobs contain REST List Parameter definitions in their configuration
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Examine parameter name field in affected jobsOpen each identified job > Configure > scroll to This build is parameterized section. Inspect the Name field for any REST List Parameter entry. The vulnerability triggers when the parameter name contains unsanitized referencesAffected if Parameter name field exists and contains values that could be interpreted as JavaScript (the vulnerability is in how name references are embedded in JavaScript code)
The environment is affected if the REST List Parameter Plugin version 1.3.0 or earlier is installed AND at least one job uses this plugin with configurable parameters, since the XSS flaw lies in how parameter name references are handled in JavaScript output.
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 the REST List Parameter Plugin to version 1.3.1 or later which includes proper output encoding. Until then, restrict Job/Configure permission to only trusted users.
Fix this in Rest List Parameter
Scoped from the published advisory
- Consultation2.0 h
- Implementation3.0 h
- Testing3.0 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 $2,800.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2021-21635 — 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-2021-21635 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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- Version or environment caveats, and links to real fixes
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