CVE-2020-2301 in Active Directory Plugin
Summary
by MITRE • 11/04/2020
Jenkins Active Directory Plugin 2.19 and earlier allows attackers to log in as any user with any password while a successful authentication of that user is still in the optional cache when using Windows/ADSI mode.
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Analysis
by VulDB Data Team • 12/02/2020
The vulnerability identified as CVE-2020-2301 affects the Jenkins Active Directory Plugin version 2.19 and earlier, presenting a critical authentication bypass flaw that undermines the security of Windows/ADSI mode implementations. This issue stems from improper handling of cached authentication tokens within the plugin's architecture, creating a window of opportunity for malicious actors to exploit the system's trust mechanisms.
The technical flaw manifests when the Active Directory plugin operates in Windows/ADSI mode and maintains an optional authentication cache. Under normal circumstances, this cache serves to improve performance by storing successful authentication attempts. However, the vulnerability arises from the plugin's failure to properly validate cached credentials against the current authentication request, allowing attackers to leverage previously authenticated user sessions. The flaw essentially enables arbitrary user impersonation where an attacker can authenticate as any user in the directory with any password, provided that user's authentication is still cached within the system's temporary authentication store.
This vulnerability directly impacts the principle of least privilege and authentication integrity within Jenkins environments, potentially allowing attackers to gain unauthorized access to sensitive system resources and administrative functions. The operational impact extends beyond simple credential theft, as successful exploitation could enable attackers to execute arbitrary code, modify system configurations, or access confidential data within the Jenkins infrastructure. The vulnerability's severity is amplified in environments where Jenkins serves as a central automation hub for deployment pipelines, build systems, or other critical infrastructure components.
The security implications of this vulnerability align with CWE-287, which addresses improper authentication issues, and can be mapped to ATT&CK technique T1078 for valid accounts and T1566 for credential harvesting. Organizations running affected Jenkins versions face significant risk of privilege escalation attacks, particularly in environments where multiple users maintain access to the system and where cached authentication is enabled. The vulnerability's exploitation requires minimal technical skill and can be automated, making it particularly dangerous in large enterprise environments where the attack surface is extensive.
Mitigation strategies should prioritize immediate patching of the Jenkins Active Directory Plugin to version 2.20 or later, which addresses the cache validation flaw. Organizations should also implement additional security controls including disabling cached authentication where possible, implementing network segmentation to limit access to Jenkins systems, and monitoring authentication logs for suspicious activity patterns. Regular security assessments should verify that authentication mechanisms are properly configured and that cached credentials are handled according to security best practices. Network-level controls such as firewall rules and intrusion detection systems can help detect and prevent exploitation attempts targeting this vulnerability.