UrltriggerApplication · Jenkins
CVE-2021-21659
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 URLTrigger Plugin 0.48 and earlier does not configure its XML parser to prevent XML external entity (XXE) attacks.
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 URLTrigger Plugin versions 0.48 and earlier does not securely configure its XML parser when processing XML documents from monitored URLs. This allows remote attackers to perform XML External Entity (XXE) attacks by injecting malicious XML containing external entity references, potentially leading to disclosure of internal files or denial of service.
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
UrltriggerApplication
<= 0.48CVSS 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
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- None
- Availability
- High
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H
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 URLTrigger plugin is installedNavigate to Jenkins > Manage Jenkins > Manage Plugins > Installed tab and search for 'URLTrigger' in the list of installed pluginsAffected if The URLTrigger plugin appears in the installed plugins list
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Determine installed URLTrigger versionIn the Installed Plugins tab, locate the URLTrigger plugin and note the Version column valueAffected if The version listed is 0.48 or lower (e.g., 0.48, 0.47, 0.46, etc.)
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Identify active URLTrigger configurationsNavigate to a job that uses URLTrigger, or go to Manage Jenkins > System and look for the URLTrigger section under Configure System. Document any monitored URLs configured.Affected if There are URLTrigger configurations pointing to URLs that serve or could serve XML content (look for URLs ending in .xml or known to return XML responses)
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Check if XML monitoring is enabledIn the URLTrigger configuration for each job, examine whether the 'Watched XML' or ' XML' option is selected as the content type to monitorAffected if The plugin is configured to watch/monitor XML content from remote URLs
You are affected if the URLTrigger plugin version is 0.48 or earlier AND it is configured to monitor URLs that return XML content, as this enables the XXE vulnerability to be exploited.
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 URLTrigger Plugin to version 0.49 or later, which includes proper XML parser configuration to prevent XXE attacks. If an upgrade is not immediately possible, consider disabling URLTrigger or implementing additional input validation at the Jenkins master level.
Fix this in Urltrigger
Scoped from the published advisory
- Consultation2.0 h
- Implementation2.0 h
- Testing2.0 h
- Review / QA1.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $1,984.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2021-21659 — 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-2021-21659 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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- Verified mitigations, workarounds, and config changes
- Version or environment caveats, and links to real fixes
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