Arbitrary code execution outside sandbox

Summary

Jenkins Script Security Plugin 1402.v94c9ce464861 and earlier does not reject Groovy AST transformation annotations carrying an extensions member, allowing attackers able to run sandboxed Groovy scripts to execute code outside the sandbox if a suitable script is present on the classpath of the component that evaluates the script. A flaw was found in the Jenkins Script Security Plugin. Attackers with the ability to run sandboxed Groovy scripts can exploit this vulnerability to execute arbitrary code outside the sandbox environment. This is due to the plugin's failure to reject Groovy Abstract Syntax Tree (AST) transformation annotations that include an extensions member, allowing unauthorized script execution if a suitable script exists on the classpath. This flaw has an Important impact as the Jenkins Script Security Plugin shipped in Red Hat OpenShift Container Platform is susceptible to a sandbox bypass. An authenticated attacker with the ability to run sandboxed Groovy scripts can exploit improperly handled AST transformation annotations to execute arbitrary code outside the sandbox on the Jenkins controller. Exploitation requires a suitable script to be present on the classpath, increasing attack complexity. Red Hat severity: Important — CVSS 8.5 (CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:H). Weakness: CWE-917. No fixing RHSA erratum has published yet; monitor the Red Hat CVE page and patch when it ships.