CVE-2025-24399 in OpenId Connect Authentication Plugin
Summary
by MITRE • 01/22/2025
Jenkins OpenId Connect Authentication Plugin 4.452.v2849b_d3945fa_ and earlier, except 4.438.440.v3f5f201de5dc, treats usernames as case-insensitive, allowing attackers on Jenkins instances configured with a case-sensitive OpenID Connect provider to log in as any user by providing a username that differs only in letter case, potentially gaining administrator access to Jenkins.
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Analysis
by VulDB Data Team • 03/18/2025
The vulnerability identified as CVE-2025-24399 affects the Jenkins OpenId Connect Authentication Plugin version 4.452.v2849b_d3945fa_ and earlier, excluding version 4.438.440.v3f5f201de5dc. This issue stems from a fundamental design flaw in how the plugin handles user authentication when integrated with OpenID Connect providers that enforce case-sensitive username validation. The vulnerability manifests when Jenkins instances are configured to work with identity providers that require case-sensitive user identification, creating a critical mismatch between the authentication system and the underlying identity provider requirements.
The technical flaw lies in the plugin's implementation where it performs case-insensitive username comparisons during the authentication process. When a user attempts to log in through OpenID Connect, the plugin accepts any variation of the username case that matches the target user account, regardless of the actual case sensitivity requirements of the upstream identity provider. This behavior creates a privilege escalation vector where an attacker can exploit the case-insensitive matching to impersonate users with different case variations of their usernames, potentially accessing accounts with elevated privileges including administrative rights.
This vulnerability directly impacts the principle of least privilege and authentication integrity within Jenkins environments. The operational consequences are severe as attackers can leverage this weakness to gain unauthorized access to Jenkins instances, potentially escalating privileges to administrator level. The impact extends beyond simple unauthorized access to include potential data breaches, system compromise, and unauthorized modifications to Jenkins configurations, build jobs, and access controls. The vulnerability affects organizations that rely on OpenID Connect for centralized authentication and have configured their Jenkins instances to work with case-sensitive identity providers.
The security implications align with CWE-287 which addresses improper authentication issues, and the attack pattern maps to ATT&CK technique T1078.004 for valid accounts and T1566.001 for credential stuffing attacks. Organizations using affected versions of the Jenkins OpenId Connect Authentication Plugin should immediately upgrade to version 4.438.440.v3f5f201de5dc or later, which contains the necessary patch to address the case sensitivity handling. Additionally, administrators should review their OpenID Connect provider configurations to ensure proper case sensitivity enforcement and implement monitoring for suspicious authentication patterns that could indicate exploitation attempts.
The vulnerability demonstrates the critical importance of proper authentication implementation and the potential security risks introduced when authentication systems fail to maintain consistency with upstream identity provider requirements. Organizations should conduct thorough security assessments of their authentication configurations and implement proper access controls to prevent unauthorized privilege escalation. Regular security updates and patch management processes become essential to protect against such vulnerabilities that can compromise entire Jenkins infrastructures and the sensitive data they manage.