CVE-2020-2191 in Self-Organizing Swarm Plug-in Modules Plugin
Summary
by MITRE
Jenkins Self-Organizing Swarm Plug-in Modules Plugin 3.20 and earlier does not check permissions on API endpoints that allow adding and removing agent labels.
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Analysis
by VulDB Data Team • 06/04/2020
The vulnerability identified as CVE-2020-2191 affects the Jenkins Self-Organizing Swarm Plug-in Modules Plugin version 3.20 and earlier, representing a critical authorization flaw that undermines the security posture of Jenkins continuous integration servers. This issue stems from insufficient permission validation within the plugin's application programming interface endpoints, creating a pathway for unauthorized users to manipulate agent label configurations within the Jenkins environment. The flaw specifically impacts the plugin's ability to enforce proper access controls when executing operations related to agent label management, potentially allowing malicious actors to alter the operational characteristics of Jenkins agents without proper authentication or authorization.
The technical implementation of this vulnerability resides in the plugin's API endpoint design, where the system fails to validate user credentials or roles before permitting modifications to agent labels. This represents a direct violation of the principle of least privilege and demonstrates a classic authorization bypass vulnerability that falls under the CWE-863 category of "Incorrect Authorization." The flaw enables attackers to perform unauthorized actions through the exposed endpoints, specifically targeting the functionality that allows adding and removing labels from Jenkins agents. When an attacker successfully exploits this vulnerability, they can manipulate which labels are associated with specific agents, potentially enabling them to gain access to restricted resources or disrupt normal operational workflows.
The operational impact of this vulnerability extends beyond simple privilege escalation, as it can enable attackers to compromise the integrity of the entire Jenkins infrastructure. By manipulating agent labels, malicious actors can potentially cause agents to execute jobs intended for different environments or access sensitive data and resources that should be restricted. This vulnerability particularly affects organizations that rely on Jenkins for continuous integration and deployment processes, where agent labels often determine which jobs can be executed on specific agents and which resources those agents can access. The ability to modify label assignments without proper authorization creates opportunities for attackers to move laterally within the Jenkins environment and potentially access systems that should be protected from unauthorized access.
Organizations should prioritize immediate remediation of this vulnerability by upgrading to Jenkins Self-Organizing Swarm Plug-in Modules Plugin version 3.21 or later, which contains the necessary permission checks to address the authorization bypass issue. Additionally, administrators should review and validate existing access controls within their Jenkins installations to ensure that proper role-based access controls are implemented across all plugin modules. The vulnerability demonstrates the critical importance of implementing proper API endpoint validation and authorization checks, particularly in continuous integration environments where automated systems handle sensitive operations. Security teams should also consider implementing network-level restrictions to limit access to Jenkins API endpoints and establish monitoring for unauthorized attempts to modify agent configurations, as this vulnerability aligns with techniques described in the ATT&CK framework under the privilege escalation and defense evasion tactics.