CVE-2015-5298 in Google Login Plugin
Summary
by MITRE • 07/07/2022
The Google Login Plugin (versions 1.0 and 1.1) allows malicious anonymous users to authenticate successfully against Jenkins instances that are supposed to be locked down to a particular Google Apps domain through client-side request modification.
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Analysis
by VulDB Data Team • 07/20/2022
The vulnerability described in CVE-2015-5298 represents a critical authentication bypass flaw within the Google Login Plugin for Jenkins, affecting versions 1.0 and 1.1. This issue fundamentally undermines the security controls designed to restrict Jenkins access to specific Google Apps domains, creating a significant risk for organizations relying on domain-based authentication for their continuous integration and deployment systems. The flaw exploits a weakness in the plugin's validation mechanism that fails to properly verify the authenticity of authentication requests.
The technical implementation of this vulnerability stems from insufficient server-side validation of client-side parameters that should be immutable during the authentication flow. Malicious actors can manipulate request parameters to bypass the intended domain restrictions, allowing unauthorized users to gain access to Jenkins instances that should only permit legitimate members of a specific Google Apps domain. This client-side request modification enables attackers to authenticate as users from the allowed domain without possessing valid credentials, effectively circumventing the intended security boundaries.
The operational impact of this vulnerability extends beyond simple unauthorized access, as it compromises the integrity of Jenkins-based CI/CD pipelines and can lead to supply chain attacks. Organizations using Jenkins with Google Apps domain restrictions may experience unauthorized code deployments, data exfiltration, or system compromise when attackers exploit this flaw. The vulnerability particularly affects environments where Jenkins serves as a central automation platform, as it undermines the trust model that security administrators rely upon to control access to critical build infrastructure.
This vulnerability aligns with CWE-285, which addresses improper authorization issues, and demonstrates characteristics consistent with ATT&CK technique T1078.004 for valid accounts, as attackers can leverage legitimate domain accounts through manipulation of authentication parameters. The flaw also relates to CWE-345, which covers insufficient verification of data authenticity, since the plugin fails to properly validate the integrity of authentication requests. Organizations should implement immediate mitigations including plugin updates to versions that address the authentication bypass, network segmentation to restrict Jenkins access, and monitoring for unusual authentication patterns. Additionally, administrators should consider implementing additional authentication layers such as two-factor authentication and regular security audits of authentication plugins to prevent similar vulnerabilities from compromising their CI/CD environments.