CVE-2023-27903: Medium severity jenkins lts vulnerability
Jenkins 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 file parameter through the CLI, potentially allowing attackers with access to the Jenkins controller file system to read and write the file before it is used.
Other sources
When triggering a build from the Jenkins CLI, Jenkins creates a temporary file on the controller if a file parameter is provided through the CLI’s standard input.
Jenkins 2.393 and earlier, LTS 2.375.3 and earlier, and , and LTS prior to 2.387.1 creates this temporary file in the default 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 used in the build.
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 allows attackers to read the temporary file. Jenkins 2.394, LTS 2.375.4, and LTS 2.387.1 creates the temporary file with more restrictive permissions.
As a workaround, you can set a different path as your default temporary directory using the Java system property java.io.tmpdir, if you’re concerned about this issue but unable to immediately update Jenkins.
Affected Software
Event History
Frequently Asked Questions
What is the vulnerability ID of this Jenkins vulnerability?
The vulnerability ID is CVE-2023-27903.
What is the severity rating of CVE-2023-27903?
The severity rating of CVE-2023-27903 is medium with a value of 4.4.
How can an attacker exploit CVE-2023-27903?
An attacker with access to the Jenkins controller file system can exploit CVE-2023-27903 by reading temporary files created with default permissions.
How can I fix CVE-2023-27903?
To fix CVE-2023-27903, update Jenkins to version 2.394 or later, or LTS to version 2.375.4 or later.
Where can I find more information about CVE-2023-27903?
You can find more information about CVE-2023-27903 in the Jenkins security advisory at https://www.jenkins.io/security/advisory/2023-03-08/#SECURITY-3058 and the Red Hat Security Advisory at https://access.redhat.com/errata/RHSA-2023:1655.