CVE-2023-43496

Jenkins creates a temporary file when a plugin is deployed directly from a URL.

Jenkins 2.423 and earlier, LTS 2.414.1 and earlier creates this temporary file in the system temporary directory with the default permissions for newly created files.

If these permissions are overly permissive, they may allow attackers with access to the Jenkins controller file system to read and write the file before it is installed in Jenkins, potentially resulting in arbitrary code execution.

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.

This issue complements SECURITY-2823, which affected plugins uploaded from an administrator’s computer.
Jenkins 2.424, LTS 2.414.2 creates the temporary file 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.

CVE-2023-43496 has a CVSS score of 7.0 (High). The vector is requires local access, low privileges required, and no user interaction. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (2.414.2, 2.424); upgrading removes the vulnerable code path.

Kodem intelligence

1. What is CVE-2023-43496? CVE-2023-43496 is a high-severity security vulnerability in org.jenkins-ci.main:jenkins-core (maven), affecting versions >= 2.50, < 2.414.2. It is fixed in 2.414.2, 2.424.
2. How severe is CVE-2023-43496? CVE-2023-43496 has a CVSS score of 7.0 (High). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
3. Which versions of org.jenkins-ci.main:jenkins-core are affected by CVE-2023-43496? org.jenkins-ci.main:jenkins-core (maven) versions >= 2.50, < 2.414.2 is affected.
4. Is there a fix for CVE-2023-43496? Yes. CVE-2023-43496 is fixed in 2.414.2, 2.424. Upgrade to this version or later.
5. Is CVE-2023-43496 exploitable, and should I be worried? Whether CVE-2023-43496 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
6. What actually determines whether CVE-2023-43496 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
7. How do I fix CVE-2023-43496?
   • Upgrade org.jenkins-ci.main:jenkins-core to 2.414.2 or later
   • Upgrade org.jenkins-ci.main:jenkins-core to 2.424 or later

Other vulnerabilities in org.jenkins-ci.main:jenkins-core