JenkinsApplication
CVE-2023-27899
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 2.393 and earlier, LTS 2.375.3 and earlier creates a temporary file in the default temporary directory with the default permissions for newly created files when uploading a plugin for installation, potentially allowing attackers with access to the Jenkins controller file system to read and write the file before it is used, potentially resulting in arbitrary code execution.
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 creates temporary files in the default system temp directory with default file permissions when uploading plugins for installation. An attacker with filesystem access to the Jenkins controller can read or modify these temp files before they are processed, potentially allowing injection of malicious content leading to arbitrary code execution during plugin installation.
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
< 2.375.4< 2.394CVSS 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
- Local
- Complexity
- High
- Privileges
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/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 checksWork through these to decide whether this CVE applies to you.
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Determine installed Jenkins versionNavigate to Manage Jenkins > About Jenkins, or access /api/json?tree=version from the Jenkins URL, or run: java -jar jenkins.war --versionAffected if The version shown is less than 2.375.4 (LTS) or less than 2.394 (weekly)
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Verify temp directory permissionsCheck the permissions on the system temp directory (typically /tmp on Linux or %TEMP% on Windows). Run 'ls -ld /tmp' or inspect the directory properties in Windows ExplorerAffected if The temp directory is writable by users other than the Jenkins service account (world-writable or has excessive ACLs)
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Confirm plugin upload/install capabilityNavigate to Manage Jenkins > Manage Plugins > Available tab, or attempt to upload a .hpi file via Manage Jenkins > Manage Plugins > Advanced > Upload PluginAffected if The user has permissions to install or upload plugins (administrator access)
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Assess filesystem access threat modelReview which users have access to the Jenkins controller filesystem, particularly the temp directory. Check for untrusted users or shared/hybrid environmentsAffected if Untrusted users or processes can access the Jenkins controller filesystem
You are affected if running Jenkins version less than 2.375.4 or less than 2.394 AND the temp directory is accessible to untrusted users who could intercept plugin upload files before processing.
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 · scoped2.375.42.394
Upgrade Jenkins to version 2.394 or later (LTS 2.375.4 or later). Alternatively, ensure strict filesystem permissions on the temp directory and limit controller filesystem access to trusted users.
Jenkins LTS 2.375.4 or later (or Jenkins 2.394+ for weekly releases)
- 1. Back up your Jenkins home directory and configuration before upgrading
- 2. For Jenkins LTS users: Upgrade to Jenkins LTS 2.375.4 or later
- 3. For Jenkins weekly users: Upgrade to Jenkins 2.394 or later
- 4. Restart the Jenkins service after upgrading
- 5. Verify that plugin upload functionality works correctly
- 6. Confirm the temporary file handling issue is resolved by checking that uploaded plugins are processed with secure permissions
Generated from the published advisory — verify against the referenced sources before acting.
Fix this in Jenkins
Scoped from the published advisory
- Consultation2.0 h
- Implementation2.0 h
- Testing4.0 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 $2,464.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2023-27899 — 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-2023-27899 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