CVE-2023-43497 — jenkins-core
HIGHCVE-2023-43497 is a high-severity (CVSS 8.1) Unrestricted File Upload vulnerability in org.jenkins-ci.main:jenkins-core. A fix is available for org.jenkins-ci.main:jenkins-core — see the affected versions and patch details below.
Jenkins temporary uploaded file created with insecure permissions
Exploitation Status
No confirmed exploitation observed yet
- A successful exploit gives an attacker total control of the affected component, not partial access.
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for CVE-2023-43497.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
Where this sits among everything scored
Real-World Exposure
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
In Jenkins 2.423 and earlier, LTS 2.414.1 and earlier, uploaded files processed via the Stapler web framework and the Jenkins API MultipartFormDataParser create temporary files in the system temporary directory with the default permissions for newly created files.
If these permissions are overly permissive, attackers with access to the system temporary directory may be able to read and write the file before it is used.
This vulnerability only affects operating systems using a shared temporary directory for all users (typically Linux). Additionally, the default permissions for newly created files generally only allow attackers to read the temporary file, but not write to it. Jenkins 2.424, LTS 2.414.2 creates the temporary files in a subdirectory with more restrictive permissions.
As a workaround, you can change your default temporary-file directory using the Java system property java.io.tmpdir, if you’re concerned about this issue but unable to immediately update Jenkins.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| ☕Maven | org.jenkins-ci.main:jenkins-core | ≥ 2.50&&< 2.414.2 | 2.414.2org.jenkins-ci.main:jenkins-core:2.414.2 |
| ☕Maven | org.jenkins-ci.main:jenkins-core | ≥ 2.415&&< 2.424 | 2.424org.jenkins-ci.main:jenkins-core:2.424 |
Affected Products
jenkinsjenkinsDetection & 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, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update org.jenkins-ci.main:jenkins-core to 2.414.2 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2023-43497 is resolved across your whole dependency graph.
Workarounds
Treat uploaded files as untrusted until proven otherwise: validate the actual content type rather than the supplied extension, store uploads outside the web root on a volume mounted without execute permission, and rename them to server-generated identifiers so an attacker cannot choose the path a request will later resolve.
Frequently Asked Questions
Is CVE-2023-43497 in your dependencies?
Find it across Maven, including transitive dependencies.