CVE-2024-23897

A flaw was found in Jenkins, which 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 the “@” character followed by a file path in an argument with the file’s contents (expandAtFiles). This feature is enabled by default; Jenkins 2.441 and earlier as well as LTS 2.426.2 and earlier do not disable it.

Mitigation

Disabling access to the CLI is expected to prevent exploitation completely. Doing so is strongly recommended to administrators unable to immediately update to Jenkins 2.442, LTS 2.426.3 or LTS 2.440.1. Applying this workaround does not require a Jenkins restart.