A cross-site request forgery vulnerability exists in Jenkins Warnings Next Generation Plugin 2.1.1 and earlier in src/main/java/io/jenkins/plugins/analysis/warnings/groovy/GroovyParser.java that allows attackers to execute arbitrary code via a form validation HTTP endpoint.

Affected: Maven: io.jenkins.plugins:warnings-ng

Jenkins Warnings Next Generation Plugin has a form validation HTTP endpoint used to validate a Groovy script through compilation, which was not subject to sandbox protection. The endpoint checked for the Overall/RunScripts permission, but did not require POST requests, so it was vulnerable to cross-site request forgery (CSRF). This allowed attackers to execute arbitrary code on the Jenkins controller by applying AST transforming annotations such as `@Grab` to source code elements.

The affected HTTP endpoint now applies a safe Groovy compiler configuration preventing the use of unsafe AST transforming annotations. Additionally, the form validation HTTP endpoint now requires that requests be sent via POST to prevent CSRF.