CVE-2020-2276 in Selection tasks Plugin
Summary
by MITRE
Jenkins Selection tasks Plugin 1.0 and earlier executes a user-specified program on the Jenkins controller, allowing attackers with Job/Configure permission to execute an arbitrary system command on the Jenkins controller as the OS user that the Jenkins process is running as.
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Analysis
by VulDB Data Team • 09/16/2020
The vulnerability identified as CVE-2020-2276 affects the Jenkins Selection tasks Plugin version 1.0 and earlier, presenting a critical security risk that enables privilege escalation and arbitrary code execution on the Jenkins controller. This flaw arises from insufficient input validation and improper command execution handling within the plugin's functionality, creating a pathway for attackers to execute system commands with elevated privileges. The vulnerability specifically targets the Jenkins controller's execution environment, making it particularly dangerous for organizations that rely on Jenkins for continuous integration and deployment processes. The attack vector requires only Job/Configure permission, which is often granted to developers and build operators, significantly expanding the potential attack surface.
The technical flaw manifests when the plugin processes user-specified programs on the Jenkins controller without adequate sanitization of input parameters. This lack of proper validation allows malicious actors to inject arbitrary commands that get executed in the context of the Jenkins process. The vulnerability stems from improper handling of command construction and execution, where user-provided input directly influences system command invocation. The plugin's design fails to implement proper input filtering, escaping, or sandboxing mechanisms, creating a command injection vulnerability that can be exploited to execute arbitrary system commands. This flaw aligns with CWE-78, which describes improper neutralization of special elements used in OS commands, and represents a classic example of command injection in enterprise automation platforms. The vulnerability can be exploited through the Jenkins web interface where users with minimal permissions can configure jobs, making it particularly insidious in environments where job configuration permissions are widely distributed.
The operational impact of CVE-2020-2276 extends far beyond simple privilege escalation, as successful exploitation can lead to complete compromise of the Jenkins controller and potentially the entire build infrastructure. Attackers can leverage this vulnerability to execute commands as the operating system user running the Jenkins process, which typically has significant privileges within the build environment. This could result in unauthorized access to source code repositories, exposure of sensitive build artifacts, data exfiltration, and potential lateral movement within the network. The vulnerability also enables attackers to escalate privileges further by exploiting the Jenkins controller's access to other systems and services. Organizations using Jenkins for production builds face severe risks including supply chain attacks, where malicious code could be injected into build processes and distributed to end users. The impact is particularly severe in DevOps environments where Jenkins serves as a central automation hub for critical business processes. According to ATT&CK framework, this vulnerability maps to T1059.001 (Command and Scripting Interpreter: PowerShell) and T1068 (Exploitation for Privilege Escalation), representing the exploitation techniques that attackers would employ to leverage this weakness.
Mitigation strategies for CVE-2020-2276 should prioritize immediate plugin updates to version 1.1 or later, which contain proper input validation and command execution safeguards. Organizations must implement comprehensive access control measures, ensuring that only trusted personnel have Job/Configure permissions, and regularly audit these permissions to prevent unnecessary access. The Jenkins controller should be configured with minimal required privileges, running as a dedicated low-privilege user account rather than as root or administrator. Network segmentation and firewall rules should restrict access to the Jenkins controller to only necessary systems and users. Additional defensive measures include implementing Jenkins security plugins, enabling audit logging for job configuration changes, and conducting regular security assessments of the Jenkins environment. Organizations should also consider implementing runtime application protection and intrusion detection systems to monitor for exploitation attempts. The remediation process must include thorough testing of updated plugins in staging environments before deployment to production systems. Security teams should also review and update their incident response procedures to account for potential exploitation of this vulnerability, ensuring rapid detection and containment of any successful attacks. Regular vulnerability scanning and security monitoring should be implemented to identify similar weaknesses in other Jenkins plugins and the overall automation infrastructure.