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.

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.

The following flaw was found in Jenkins:

A vulnerability in the Jenkins remoting module allowed unauthenticated remote attackers to open a JRMP listener on the server hosting the Jenkins master process, which allowed arbitrary code execution.

External References:

https://wiki.jenkins-ci.org/display/SECURITY/Jenkins+Security+Advisory+2016-02-24

Jenkins Plugin Installation Manager Tool 2.1.3 and earlier does not verify plugin downloads.

Jenkins JIRA Plugin 3.0.10 and earlier does not declare the correct (folder) scope for per-folder Jira site definitions, allowing users to select and use credentials with System scope.

A sandbox bypass vulnerability involving various casts performed implicitly by the Groovy language runtime in Jenkins Script Security Plugin 1183.v774b0b0aa451 and earlier allows attackers with permission to define and run sandboxed scripts, including Pipelines, to bypass the sandbox protection and execute arbitrary code in the context of the Jenkins controller JVM.

A sandbox bypass vulnerability involving casting an array-like value to an array type in Jenkins Script Security Plugin 1183.v774b0b0aa451 and earlier allows attackers with permission to define and run sandboxed scripts, including Pipelines, to bypass the sandbox protection and execute arbitrary code in the context of the Jenkins controller JVM.

A sandbox bypass vulnerability in Jenkins Pipeline: Groovy Libraries Plugin 612.v84da9c54906d and earlier allows attackers with permission to define untrusted Pipeline libraries and to define and run sandboxed scripts, including Pipelines, to bypass the sandbox protection and execute arbitrary code in the context of the Jenkins controller JVM.

A sandbox bypass vulnerability involving various casts performed implicitly by the Groovy language runtime in Jenkins Pipeline: Groovy Plugin 2802.v5ea628154bc2 and earlier allows attackers with permission to define and run sandboxed scripts, including Pipelines, to bypass the sandbox protection and execute arbitrary code in the context of the Jenkins controller JVM.

A sandbox bypass vulnerability in Jenkins Pipeline: Deprecated Groovy Libraries Plugin 583.vf3b454e43966 and earlier allows attackers with permission to define untrusted Pipeline libraries and to define and run sandboxed scripts, including Pipelines, to bypass the sandbox protection and execute arbitrary code in the context of the Jenkins controller JVM.

A sandbox bypass vulnerability involving crafted constructor bodies and calls to sandbox-generated synthetic constructors in Jenkins Script Security Plugin 1183.v774b0b0aa451 and earlier allows attackers with permission to define and run sandboxed scripts, including Pipelines, to bypass the sandbox protection and execute arbitrary code in the context of the Jenkins controller JVM.

A flaw was found in the Jenkins Workflow Remote Loader plugin. An unsafe whitelist entry was made that allowed invoking arbitrary methods and bypassing sandbox protection. The highest threat from this vulnerability is to data confidentiality and integrity as well as system availability.

Jenkins Puppet Enterprise Pipeline 1.3.1 and earlier specifies unsafe values in its custom Script Security whitelist, allowing attackers able to execute Script Security protected scripts to execute arbitrary code.

Jenkins Kubernetes :: Pipeline :: Arquillian Steps Plugin provides a custom whitelist for script security that allowed attackers to invoke arbitrary methods, bypassing typical sandbox protection.

A sandbox bypass vulnerability in Jenkins Script Security Plugin 1.64 and earlier related to the handling of default parameter expressions in constructors allowed attackers to execute arbitrary code in sandboxed scripts.

A sandbox bypass vulnerability exists in Jenkins Job DSL Plugin 1.71 and earlier in job-dsl-core/src/main/groovy/javaposse/jobdsl/dsl/AbstractDslScriptLoader.groovy, job-dsl-plugin/build.gradle, job-dsl-plugin/src/main/groovy/javaposse/jobdsl/plugin/JobDslWhitelist.groovy, job-dsl-plugin/src/main/groovy/javaposse/jobdsl/plugin/SandboxDslScriptLoader.groovy that allows attackers with control over Job DSL definitions to execute arbitrary code on the Jenkins master JVM.

A sandbox bypass vulnerability exists in Jenkins Matrix Project Plugin 1.13 and earlier in pom.xml, src/main/java/hudson/matrix/FilterScript.java that allows attackers with Job/Configure permission to execute arbitrary code on the Jenkins master JVM.

A sandbox bypass vulnerability in Jenkins Script Security Plugin 1.74 and earlier allows attackers with permission to define sandboxed scripts to provide crafted return values or script binding content that can result in arbitrary code execution on the Jenkins controller JVM.

Jenkins Kubernetes :: Pipeline :: Kubernetes Steps Plugin provides a custom whitelist for script security that allowed attackers to invoke arbitrary methods, bypassing typical sandbox protection.

A sandbox bypass vulnerability in Jenkins ontrack Plugin 3.4 and earlier allowed attackers with control over ontrack DSL definitions to execute arbitrary code on the Jenkins master JVM.

A sandbox bypass vulnerability exists in Jenkins Email Extension Plugin 2.64 and earlier in pom.xml, src/main/java/hudson/plugins/emailext/ExtendedEmailPublisher.java, src/main/java/hudson/plugins/emailext/plugins/content/EmailExtScript.java, src/main/java/hudson/plugins/emailext/plugins/content/ScriptContent.java, src/main/java/hudson/plugins/emailext/plugins/trigger/AbstractScriptTrigger.java that allows attackers with Job/Configure permission to execute arbitrary code on the Jenkins master JVM.

In Jenkins Email Extension Plugin 2.93 and earlier, templates defined inside a folder were not subject to Script Security protection, allowing attackers able to define email templates in folders to bypass the sandbox protection and execute arbitrary code in the context of the Jenkins controller JVM.

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 sandbox bypass vulnerability involving crafted constructor bodies in Jenkins Script Security Plugin 1335.vf07d9ce377ae and earlier allows attackers with permission to define and run sandboxed scripts, including Pipelines, to bypass the sandbox protection and execute arbitrary code in the context of the Jenkins controller JVM.

In Jenkins WSO2 Oauth Plugin 1.0 and earlier, authentication claims are accepted without validation by the "WSO2 Oauth" security realm, allowing unauthenticated attackers to log in to controllers using this security realm using any username and any password, including usernames that do not exist.

The following flaw was found in Jenkins:

Unsafe deserialization allows unauthenticated remote attackers to run arbitrary code on the Jenkins master.

This flaw could allow unauthenticated remote attackers to run arbitrary code on Jenkins.

Mitigation:

https://jenkins-ci.org/content/mitigating-unauthenticated-remote-code-execution-0-day-jenkins-cli

External References:

https://wiki.jenkins-ci.org/display/SECURITY/Jenkins+Security+Advisory+2015-11-11

Jenkins before 1.650 and LTS before 1.642.2 do not use a constant-time algorithm to verify CSRF tokens, which makes it easier for remote attackers to bypass a CSRF protection mechanism via a brute-force approach.

FilePath#renameTo and FilePath#moveAllChildrenTo in Jenkins 2.318 and earlier, LTS 2.303.2 and earlier only check 'read' agent-to-controller access permission on the source path, instead of 'delete'.

Jenkins 2.318 and earlier, LTS 2.303.2 and earlier does not limit agent read/write access to the libs/ directory inside build directories when using the FilePath APIs. This directory is used by the Pipeline: Shared Groovy Libraries Plugin to store copies of shared libraries.

This allows attackers in control of agent processes to replace the code of a trusted library with a modified variant, resulting in unsandboxed code execution in the Jenkins controller process.

Jenkins 2.319, LTS 2.303.3 prohibits agent read/write access to the libs/ directory inside build directories.

If you are unable to immediately upgrade to Jenkins 2.319, LTS 2.303.3, you can install the Remoting Security Workaround Plugin. It will prevent all agent-to-controller file access using FilePath APIs. Because it is more restrictive than Jenkins 2.319, LTS 2.303.3, more plugins are incompatible with it. Make sure to read the plugin documentation before installing it.

It is not easily possible to customize the file access rules to prohibit access to the libs/ directory specifically, as built-in rules (granting access to <BUILDDIR> contents) would take precedence over a custom rule prohibiting access.

FilePath#toURI, FilePath#hasSymlink, FilePath#absolutize, FilePath#isDescendant, and FilePath#getDiskSpace do not check any permissions in Jenkins 2.318 and earlier, LTS 2.303.2 and earlier.