Jenkins: community verdicts

Jenkins versions 2.56 and earlier as well as 2.46.1 LTS and earlier are vulnerable to an unauthenticated remote code execution. An unauthenticated remote code execution vulnerability allowed attackers to transfer a serialized Java `SignedObject` object to the Jenkins CLI, that would be deserialized using a new `ObjectInputStream`, bypassing the existing blacklist-based protection mechanism. We're fixing this issue by adding `SignedObject` to the blacklist. We're also backporting the new HTTP CLI protocol from Jenkins 2.54 to LTS 2.46.2, and deprecating the remoting-based (i.e. Java serialization) CLI protocol, disabling it by default.

Jenkins 2.441 and earlier, LTS 2.426.2 and earlier does not disable a feature of its CLI command parser that replaces an '@' character followed by a file path in an argument with the file's contents, allowing unauthenticated attackers to read arbitrary files on the Jenkins controller file system.

A code execution vulnerability exists in the Stapler web framework used by Jenkins 2.153 and earlier, LTS 2.138.3 and earlier in stapler/core/src/main/java/org/kohsuke/stapler/MetaClass.java that allows attackers to invoke some methods on Java objects by accessing crafted URLs that were not intended to be invoked this way.

A sandbox bypass vulnerability exists in Jenkins Pipeline: Groovy Plugin 2.63 and earlier in pom.xml, src/main/java/org/jenkinsci/plugins/workflow/cps/CpsGroovyShell.java that allows attackers able to control pipeline scripts to execute arbitrary code on the Jenkins master JVM.

A sandbox bypass vulnerability exists in Jenkins Script Security Plugin 1.53 and earlier in src/main/java/org/jenkinsci/plugins/scriptsecurity/sandbox/groovy/GroovySandbox.java, src/main/java/org/jenkinsci/plugins/scriptsecurity/sandbox/groovy/SecureGroovyScript.java that allows attackers with Overall/Read permission to execute arbitrary code on the Jenkins master JVM.

The Fingerprints pages in Jenkins before 1.638 and LTS before 1.625.2 might allow remote attackers to obtain sensitive job and build name information via a direct request.

In Jenkins 2.567 and earlier, LTS 2.555.2 and earlier, it is possible for attackers to have Jenkins deserialize arbitrary types defined in Jenkins core or plugins from an attacker-controlled `config.xml` submission in a way that allows them to handle HTTP requests afterwards. This can be used to impersonate any user and send HTTP requests on their behalf, up to and including use of the Script Console to run arbitrary code, or to read arbitrary files from the Jenkins controller.