GHSA-6f9g-cxwr-q5jr
CRITICALArbitrary file read vulnerability through the Jenkins CLI can lead to RCE
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
Blast Radius
org.jenkins-ci.main:jenkins-core☕org.jenkins-ci.main:jenkins-core☕org.jenkins-ci.main:jenkins-coreReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects Maven packages — download data is not available via public APIs for these ecosystems.
Description
Jenkins has a built-in command line interface (CLI) to access Jenkins from a script or shell environment.
Jenkins uses the args4j library to parse command arguments and options on the Jenkins controller when processing CLI commands. This command parser has a feature that replaces an @ character followed by a file path in an argument with the file’s contents (expandAtFiles). This feature is enabled by default and Jenkins 2.441 and earlier, LTS 2.426.2 and earlier does not disable it.
This allows attackers to read arbitrary files on the Jenkins controller file system using the default character encoding of the Jenkins controller process.
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Attackers with Overall/Read permission can read entire files.
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Attackers without Overall/Read permission can read the first few lines of files. The number of lines that can be read depends on available CLI commands. As of publication of this advisory, the Jenkins security team has found ways to read the first three lines of files in recent releases of Jenkins without having any plugins installed, and has not identified any plugins that would increase this line count.
Binary files containing cryptographic keys used for various Jenkins features can also be read, with some limitations (see note on binary files below). As of publication, the Jenkins security team has confirmed the following possible attacks in addition to reading contents of all files with a known file path. All of them leverage attackers' ability to obtain cryptographic keys from binary files, and are therefore only applicable to instances where that is feasible.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| ☕Maven | org.jenkins-ci.main:jenkins-core | ≥ 1.606&&< 2.426.3 | 2.426.3 |
| ☕Maven | org.jenkins-ci.main:jenkins-core | ≥ 2.427&&< 2.440.1 | 2.440.1 |
| ☕Maven | org.jenkins-ci.main:jenkins-core | ≥ 2.441&&< 2.442 | 2.442 |
Research use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.
Jenkins 2.441 - Local File Inclusion
by Matisse Beckandt · Apr 15, 2024
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for org.jenkins-ci.main:jenkins-core. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update org.jenkins-ci.main:jenkins-core to 2.426.3 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-6f9g-cxwr-q5jr is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether GHSA-6f9g-cxwr-q5jr is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to GHSA-6f9g-cxwr-q5jr. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is GHSA-6f9g-cxwr-q5jr in your dependencies?
O3 detects GHSA-6f9g-cxwr-q5jr across Maven dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.