CVE-2017-2603 in Jenkins
Summary
by MITRE
Jenkins before versions 2.44, 2.32.2 is vulnerable to a user data leak in disconnected agents' config.xml API. This could leak sensitive data such as API tokens (SECURITY-362).
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Analysis
by VulDB Data Team • 03/13/2023
The vulnerability identified as CVE-2017-2603 represents a critical security flaw in Jenkins continuous integration platform affecting versions prior to 2.44 and 2.32.2. This issue specifically targets the configuration management system of disconnected agents within Jenkins, creating an avenue for unauthorized data exposure. The vulnerability stems from insufficient access controls and data sanitization mechanisms within the config.xml API endpoint that handles agent configurations.
The technical implementation of this flaw allows attackers to exploit the disconnected agent configuration interface to extract sensitive information from the config.xml files. When agents disconnect from the Jenkins master, their configuration data remains accessible through the API without proper authentication checks. This creates a window where malicious actors can retrieve API tokens, credentials, and other confidential data that should remain protected within the Jenkins environment. The vulnerability operates at the application layer and specifically targets the XML configuration parsing and retrieval mechanisms used by Jenkins for agent management.
The operational impact of this vulnerability extends beyond simple data exposure, as it fundamentally compromises the security posture of Jenkins installations. Attackers who can access the config.xml API endpoint gain access to authentication tokens that could be used to escalate privileges within the Jenkins environment or to access external systems that rely on these tokens for authentication. The leaked data often includes service account tokens, build credentials, and other sensitive authentication mechanisms that could enable further compromise of the CI/CD pipeline. This vulnerability particularly affects organizations that rely heavily on distributed Jenkins architectures with multiple disconnected agents.
The security implications align with CWE-200, which addresses improper exposure of sensitive information, and can be categorized under ATT&CK technique T1552 for credentials in files. Organizations utilizing Jenkins in production environments face significant risk from this vulnerability, as it essentially allows for the unauthorized retrieval of authentication credentials that could be used to gain deeper access to the system. The vulnerability demonstrates a classic case of insufficient privilege separation between different API endpoints, where administrative configuration data is exposed to unauthorized users who should only have access to basic agent information.
Mitigation strategies should include immediate upgrade to Jenkins versions 2.44 or 2.32.2, which contain the necessary patches to address the access control issues. Organizations should also implement network segmentation to restrict access to the Jenkins API endpoints, particularly those handling agent configurations. Additional protective measures include implementing strict firewall rules that limit access to Jenkins administrative interfaces, enabling proper authentication and authorization controls, and conducting regular security audits of Jenkins configurations. The patch addresses the root cause by implementing proper access validation before exposing sensitive configuration data through the API, ensuring that only authorized users with appropriate privileges can retrieve agent configuration information.