CVE-2018-1000058 in Pipeline: Supporting APIs Plugin
Summary
by MITRE
Jenkins Pipeline: Supporting APIs Plugin 2.17 and earlier have an arbitrary code execution due to incomplete sandbox protection: Methods related to Java deserialization like readResolve implemented in Pipeline scripts were not subject to sandbox protection, and could therefore execute arbitrary code. This could be exploited e.g. by regular Jenkins users with the permission to configure Pipelines in Jenkins, or by trusted committers to repositories containing Jenkinsfiles.
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Analysis
by VulDB Data Team • 01/03/2020
The vulnerability identified as CVE-2018-1000058 represents a critical arbitrary code execution flaw within the Jenkins Pipeline Supporting APIs Plugin version 2.17 and earlier. This security weakness stems from insufficient sandbox protection mechanisms that fail to adequately restrict dangerous Java deserialization methods within pipeline scripts. The vulnerability specifically targets the readResolve method implementation which allows attackers to bypass security restrictions and execute malicious code directly within the Jenkins environment. The flaw exists because Jenkins developers did not properly account for the security implications of certain deserialization methods that could be invoked during pipeline execution, creating an attack surface that legitimate users could exploit without requiring elevated privileges.
The technical implementation of this vulnerability relies on the Java serialization mechanism and how Jenkins processes pipeline scripts containing maliciously crafted deserialization code. When a Jenkins user with pipeline configuration permissions creates or modifies a Jenkinsfile containing a specially crafted readResolve method, the system fails to properly sandbox this execution path. This allows the malicious code to run with the privileges of the Jenkins user, potentially leading to complete system compromise. The vulnerability operates at the core of Jenkins' pipeline processing architecture where script security is supposed to prevent dangerous operations but fails to account for deserialization methods that bypass these protections. The attack vector specifically leverages the fact that Jenkins does not adequately validate or restrict access to certain Java serialization methods during pipeline execution, creating a direct pathway for code injection.
The operational impact of this vulnerability extends far beyond simple code execution, as it fundamentally undermines the security model of Jenkins pipeline environments. Attackers can leverage this flaw to gain unauthorized access to Jenkins servers, potentially leading to data breaches, system compromise, and unauthorized access to sensitive build artifacts and credentials stored within the Jenkins environment. Regular users with pipeline configuration permissions can exploit this vulnerability without requiring administrative privileges, making it particularly dangerous in environments where multiple users have access to pipeline configuration. The vulnerability affects not just individual Jenkins instances but entire CI/CD pipelines that rely on pipeline scripts, potentially compromising the integrity of the software development lifecycle. This weakness can be exploited by both internal users with legitimate access and external attackers who gain access to repository commit permissions, creating a broad attack surface that spans from development environments to production systems.
Mitigation strategies for CVE-2018-1000058 focus primarily on immediate plugin updates and security hardening measures. Organizations should immediately upgrade to Jenkins Pipeline Supporting APIs Plugin version 2.18 or later, which contains the necessary fixes to properly sandbox deserialization methods and prevent unauthorized code execution. Additionally, administrators should implement strict pipeline security policies that limit who can configure pipelines and review all Jenkinsfile changes through automated security scanning processes. The remediation process should include disabling unnecessary pipeline features and ensuring that only trusted users have access to pipeline configuration permissions. Security teams should also implement monitoring for suspicious pipeline execution patterns and establish proper access controls to prevent unauthorized modifications to pipeline scripts. This vulnerability aligns with CWE-502 which specifically addresses unsafe deserialization and represents a classic example of insufficient input validation and inadequate sandboxing in security-critical applications. From an ATT&CK perspective, this vulnerability maps to T1059.001 for command and script injection, demonstrating how insecure deserialization can be leveraged for privilege escalation and persistent access within CI/CD environments.