dbcve.org
JenkinsApplication

CVE-2021-21695

HIGH · 8.8 CVSS v3.1 Published 2021-11-04
Fix available
A fix is available. Upgrade to 2.303.3 / 2.319 or later.
See remediation →
95/100
Remediation priority · Urgent
Remotely reachable No privileges

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 · unedited
FilePath#listFiles lists files outside directories that agents are allowed to access when following symbolic links in Jenkins 2.318 and earlier, LTS 2.303.2 and earlier.

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 confidence

A path traversal vulnerability in Jenkins FilePath.listFiles() allows agents to access files outside permitted directories when symbolic links are followed, bypassing intended security restrictions in Jenkins 2.318 and earlier/LTS 2.303.2 and earlier.

MitigationUpgrade Jenkins to version 2.319 or LTS 2.303.3 or later to patch the directory traversal vulnerability in FilePath.listFiles().

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
Affected:< 2.303.3< 2.319

CVSS 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
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/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 checks

Work through these to decide whether this CVE applies to you.

  1. Check Jenkins version
    Access the Jenkins web UI: go to Manage Jenkins > About Jenkins, or run `java -jar jenkins.war --version` from the command line
    Affected if The version is earlier than 2.303.3 (LTS) or earlier than 2.319
  2. Check for connected agents
    Go to Manage Jenkins > Manage Nodes in the web UI. Review the list of configured permanent agents and the number of connected agents
    Affected if Any agents are configured or connected, as the vulnerability specifically allows agents to bypass security restrictions
  3. Identify usage of FilePath.listFiles() in scripts
    Search job configuration files and any Pipeline scripts or Groovy code for calls to FilePath.listFiles() method. Check the Jenkins logs for entries involving listFiles operations
    Affected if Scripts, jobs, or pipelines actively call the FilePath.listFiles() method on agent nodes
  4. Check security realm and authorization configuration
    Go to Manage Jenkins > Configure Global Security. Review the Security Realm and Authorization settings to determine which users and agents have access to FilePath operations
    Affected if Agents have any file system access permissions through Matrix Authorization Strategy or similar configurations
  5. Verify symbolic link handling on agent nodes
    Inspect agent file systems for any symbolic links in directories that Jenkins jobs access. Check if agent workflows traverse symbolic links when listing directories
    Affected if Symbolic links exist in directories that Jenkins agents access and list files from

You are affected if your Jenkins version is below 2.303.3 LTS or below 2.319, you have configured agents, and those agents use FilePath.listFiles() operations on directories containing symbolic links.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

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 · scoped
Upgrade available Upgrade to 2.303.3 / 2.319 or later
Fixed in 2.303.32.319
Interim mitigation

Upgrade Jenkins to version 2.319 or LTS 2.303.3 or later to patch the directory traversal vulnerability in FilePath.listFiles().

Recommended fix High confidence

Jenkins 2.319 (weekly) or Jenkins 2.303.3 (LTS)

  1. 1. Backup your current Jenkins configuration, including $JENKINS_HOME and any plugins
  2. 2. Review the Jenkins LTS upgrade guide at https://www.jenkins.io/doc/book/upgrade/
  3. 3. Stop the Jenkins service
  4. 4. Upgrade Jenkins to version 2.319 or later for weekly releases, or version 2.303.3 or later for LTS releases
  5. 5. Start the Jenkins service
  6. 6. Verify the upgrade was successful by checking the Jenkins version in the UI (Manage Jenkins > About Jenkins)
  7. 7. Test that FilePath#listFiles now correctly restricts access to allowed directories when symbolic links are present
Caveat Standard LTS upgrade considerations apply; review the LTS upgrade guide for any plugin compatibility notes

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Jenkins Scoped from the published advisory
  • Consultation1.0 h
  • Implementation1.0 h
  • Testing2.0 h
  • Review / QA1.0 h
5.0 hours of engineering $860
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $1,376.

Scan for this in your stack

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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2021-21695 in production — separate from our analysis above.

No notes yet

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What this is

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.

What belongs here
  • 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