CredentialsApplication · Jenkins
CVE-2021-21648
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 Credentials Plugin 2.3.18 and earlier does not escape user-controlled information on a view it provides, resulting in a reflected cross-site scripting (XSS) vulnerability.
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 confidenceJenkins Credentials Plugin versions 2.3.18 and earlier contain a reflected cross-site scripting (XSS) vulnerability due to improper escaping of user-controlled input in one of its views. An attacker can inject malicious scripts through unsanitized input that gets reflected back to the user without proper HTML encoding.
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
CredentialsApplication
<= 2.3.18CVSS 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
- None
- User interaction
- Required
- Scope
- Changed
- Confidentiality
- Low
- Integrity
- Low
- Availability
- None
CVSS:3.1/AV:N/AC:L/PR:N/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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Identify if Jenkins Credentials Plugin is installedNavigate to Jenkins Manage Plugins page (Manage Jenkins > Manage Plugins) and locate the Credentials plugin in the Installed tab, or use the Jenkins CLI: java -jar jenkins-cli.jar list-pluginsAffected if The Credentials plugin appears in the installed plugins list
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Determine the installed version of the Credentials PluginIn the Installed plugins tab, find the Credentials plugin and note the Version column; alternatively, check the plugin's manifest file (credentials.jpi or credentials.hpi) in the JENKINS_HOME/plugins directoryAffected if The version listed is 2.3.18 or earlier (e.g., 2.3.18, 2.3.17, 2.3.16, etc.)
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Verify the vulnerable view is accessibleNavigate to the Credentials management page in Jenkins (typically at /credentials/ or accessible via Manage Jenkins > Manage Credentials) and check if user-controlled input fields are present in any of the viewsAffected if Users can access the Credentials plugin UI and input data without observed output encoding (the view reflects user input back without visible HTML encoding)
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Check for existing XSS indicatorsReview Jenkins logs (JENKINS_HOME/logs) and browser console for any XSS-related warnings or errors related to the Credentials plugin viewsAffected if Any logged XSS attempts or anomalies involving the Credentials plugin are found
You are affected if the Jenkins Credentials Plugin is installed with version 2.3.18 or earlier and users have access to the plugin's credential management views where unsanitized input could be reflected.
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 Credentials Plugin to version 2.3.19 or later, which includes proper output encoding for user-controlled data. If upgrading is not immediately possible, implement content security policy headers as a temporary mitigation.
Fix this in Credentials
Scoped from the published advisory
- Consultation2.0 h
- Implementation4.0 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 $3,088.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2021-21648 — 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-2021-21648 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