CVE-2019-1003001 in Pipeline Groovy Plugin
Summary
by MITRE
A sandbox bypass vulnerability exists in Pipeline: Groovy Plugin 2.61 and earlier in src/main/java/org/jenkinsci/plugins/workflow/cps/CpsFlowDefinition.java, src/main/java/org/jenkinsci/plugins/workflow/cps/CpsGroovyShellFactory.java that allows attackers with Overall/Read permission to provide a pipeline script to an HTTP endpoint that can result in arbitrary code execution on the Jenkins master JVM.
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Analysis
by VulDB Data Team • 11/26/2024
The vulnerability identified as CVE-2019-1003001 represents a critical sandbox bypass flaw in the Jenkins Pipeline: Groovy plugin, specifically affecting versions 2.61 and earlier. This security weakness resides within the core execution mechanisms of Jenkins pipeline processing, where the system fails to properly enforce security boundaries during script evaluation. The vulnerability stems from insufficient validation of user-provided Groovy scripts that are executed within the Jenkins master environment, creating a pathway for malicious actors to circumvent the intended security restrictions.
The technical implementation of this vulnerability occurs in two primary files within the plugin's codebase: CpsFlowDefinition.java and CpsGroovyShellFactory.java. These components handle the compilation and execution of Groovy-based pipeline scripts, where the sandbox protection mechanisms are inadequately enforced. Attackers with only Overall/Read permission can exploit this weakness by crafting malicious pipeline scripts that are submitted through HTTP endpoints. The flaw allows these scripts to execute with elevated privileges, effectively breaking out of the restricted execution environment that should isolate user code from the underlying Jenkins master JVM.
The operational impact of this vulnerability extends far beyond simple privilege escalation, as it enables full arbitrary code execution on the Jenkins master server. This means that an attacker who can submit pipeline scripts through the HTTP endpoint can potentially access sensitive system resources, exfiltrate data, modify configurations, or even establish persistent backdoors within the Jenkins environment. The vulnerability particularly affects organizations that rely heavily on Jenkins for continuous integration and deployment processes, as the master server typically holds extensive access to corporate networks and systems.
This vulnerability maps directly to CWE-276, which describes inadequate privileges and access controls, and aligns with ATT&CK technique T1059.007 for execution through scripting languages. The attack surface is particularly concerning because it leverages the legitimate pipeline execution functionality of Jenkins while exploiting a design flaw in the security model. Organizations using Jenkins with untrusted users or those that do not properly isolate their build environments face significant risk. The vulnerability demonstrates how sandbox mechanisms can be bypassed through careful manipulation of the Groovy execution pipeline, highlighting the importance of proper input validation and privilege separation in security-critical systems.
The recommended mitigations include immediate upgrade to Jenkins Pipeline: Groovy plugin version 2.62 or later, which contains the necessary security patches to address the sandbox bypass. Organizations should also implement additional controls such as restricting HTTP endpoint access to trusted users only, enabling proper authentication and authorization mechanisms, and monitoring pipeline script submissions for suspicious activity. Network segmentation and principle of least privilege should be enforced to minimize the potential impact if exploitation occurs. Regular security assessments of Jenkins configurations and plugins are essential to identify and remediate similar vulnerabilities before they can be exploited by threat actors.