A sandbox bypass vulnerability exists in Jenkins Script Security Plugin 1.52 and earlier in RejectASTTransformsCustomizer.java that allows attackers with Overall/Read permission to provide a Groovy script to an HTTP endpoint that can result in arbitrary code execution on the Jenkins master JVM.

Affected: Maven: org.jenkins-ci.plugins:script-security

The previously implemented script security sandbox protections prohibiting the use of unsafe AST transforming annotations such as `@Grab` ([2019-01-08 fix for SECURITY-1266](https://www.jenkins.io/security/advisory/2019-01-08/#SECURITY-1266)) could be circumvented through use of various Groovy language features:

- Use of `AnnotationCollector` - Import aliasing - Referencing annotation types using their full class name

This allowed users with Overall/Read permission, or the ability to control Jenkinsfile or sandboxed Pipeline shared library contents in SCM, to bypass the sandbox protection and execute arbitrary code on the Jenkins controller.

Using `AnnotationCollector` is now newly prohibited in sandboxed scripts such as Pipelines. Importing any of the annotations considered unsafe will now result in an error. During the compilation phase, both simple and full class names of prohibited annotations are rejected for element annotations.

jenkins-plugin-script-security: Sandbox Bypass in Script Security Plugin (SECURITY-1292) jenkins-plugin-script-security: Sandbox Bypass in Script Security Plugin (SECURITY-1320) jenkins-plugin-script-security: sandbox bypass in script security plugin jenkins-plugin-workflow-cps: Sandbox bypass in Pipeline: Groovy Plugin (SECURITY-1336(2)) jenkins-matrix-project-plugin: sandbox bypass in matrix project plugin jenkins-job-dsl-plugin: Script security sandbox bypass in Job DSL Plugin (SECURITY-1342)