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.

References

• https://nvd.nist.gov/vuln/detail/CVE-2019-1003008
• https://jenkins.io/security/advisory/2019-01-28/#SECURITY-1295%20(2)