Arbitrary file read vulnerability in Jenkins Pipeline Utility Steps Plugin

Pipeline Utility Steps Plugin implements a readProperties Pipeline step that supports interpolation of variables using the Apache Commons Configuration library.

Pipeline Utility Steps Plugin 2.13.1 and earlier does not restrict the set of enabled prefix interpolators and bundles versions of this library that enable the file: prefix interpolator by default.

This allows attackers able to configure Pipelines to read arbitrary files from the Jenkins controller file system.

Pipeline Utility Steps Plugin 2.13.2 restricts the set of prefix interpolators enabled by default to base64Decoder:, base64Encoder:, date:, urlDecoder:, and urlEncoder:.

Administrators can set the Java system property org.jenkinsci.plugins.pipeline.utility.steps.conf.ReadPropertiesStepExecution.CUSTOM_PREFIX_INTERPOLATOR_LOOKUPS to customize which prefix interpolators are enabled.