JenkinsApplication
CVE-2021-21685
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 2.318 and earlier, LTS 2.303.2 and earlier does not check agent-to-controller access to create parent directories in FilePath#mkdirs.
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 agents can create parent directories on the controller without proper permission checks through the FilePath#mkdirs method, allowing unauthorized filesystem access from agent nodes.
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
JenkinsApplication
< 2.303.3< 2.319CVSS 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
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- None
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/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 the Jenkins versionNavigate to Manage Jenkins > About Jenkins, or check the version from the Jenkins WAR file or package managerAffected if The installed version is below 2.319 (weekly releases) or below 2.303.3 (LTS releases)
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Verify if Jenkins agents are configuredGo to Manage Jenkins > Manage Nodes to see if any agents (permanent or inbound) are configured and onlineAffected if There are active or configured agent nodes connected to the controller
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Confirm agent permission settings for file operationsReview agent configuration and agent-based job configurations to see if jobs can execute code or file operations that invoke FilePath#mkdirsAffected if Agents have the ability to run builds or scripts that perform directory creation operations on the controller from agent contexts
You are affected if your Jenkins version is below 2.319 or below 2.303.3 LTS AND you have configured agents that can execute file operations like mkdirs.
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.
dbcve · scoped2.303.32.319
Upgrade to Jenkins 2.319 or LTS 2.303.3 or later which includes the access control fix for FilePath#mkdirs.
Jenkins 2.303.3 LTS or Jenkins 2.319 (weekly)
- 1. Back up your Jenkins home directory ($JENKINS_HOME) and configuration before upgrading
- 2. Review the Jenkins LTS upgrade guide at https://www.jenkins.io/doc/book/upgrading/
- 3. For LTS users: Upgrade to Jenkins 2.303.3 or later (e.g., 2.303.3 LTS)
- 4. For weekly users: Upgrade to Jenkins 2.319 or later
- 5. After upgrade, verify that agent-to-controller access control is functioning correctly
- 6. Test critical pipelines to ensure normal operation
- 7. Review controller-to-agent security settings in Manage Jenkins > Manage Nodes > Configure (or global security settings)
Generated from the published advisory — verify against the referenced sources before acting.
Fix this in Jenkins
Scoped from the published advisory
- Consultation4.0 h
- Implementation4.0 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 $3,968.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2021-21685 — 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-2021-21685 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
- No weaponised exploit code, or anything meant to cause harm
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