CVE-2017-2649 in Active Directory Plugin
Summary
by MITRE
It was found that the Active Directory Plugin for Jenkins up to and including version 2.2 did not verify certificates of the Active Directory server, thereby enabling Man-in-the-Middle attacks.
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Analysis
by VulDB Data Team • 03/10/2020
The vulnerability identified as CVE-2017-2649 affects the Active Directory Plugin for Jenkins versions up to and including 2.2, representing a critical security flaw in authentication infrastructure. This issue stems from the plugin's failure to properly validate SSL/TLS certificates when establishing connections to Active Directory servers, creating a significant attack surface that adversaries can exploit to compromise the integrity of the authentication process. The vulnerability specifically impacts organizations that rely on Jenkins for continuous integration and deployment workflows where Active Directory integration is essential for user management and access control.
The technical flaw manifests in the plugin's implementation of certificate validation mechanisms, which according to the CWE-295 standard for improper certificate validation, fails to enforce proper certificate chain verification and trust validation. This weakness allows attackers to perform man-in-the-middle attacks by presenting fraudulent certificates to Jenkins, enabling them to intercept and potentially manipulate authentication communications between the Jenkins server and Active Directory services. The vulnerability operates at the network security layer where certificate trust verification should occur, making it particularly dangerous as it undermines the fundamental security assumptions of encrypted communication channels.
The operational impact of this vulnerability extends beyond simple authentication bypasses, as it enables attackers to gain unauthorized access to Jenkins environments and potentially escalate privileges within the broader Active Directory infrastructure. Organizations using affected plugin versions face risks of credential theft, unauthorized code deployment, and potential lateral movement within their network boundaries. The attack vector requires the adversary to be positioned within the network to intercept communications, but once successful, the compromise can persist for extended periods without detection, as the fraudulent certificate validation would appear legitimate to the Jenkins system.
Mitigation strategies for CVE-2017-2649 should prioritize immediate plugin version updates to the latest available releases that implement proper certificate validation. Organizations must also consider implementing network-level protections such as certificate pinning, enhanced monitoring of authentication traffic, and regular certificate health checks. The vulnerability aligns with ATT&CK technique T1552.001 for credentials in files and T1078 for valid accounts, as attackers can leverage compromised authentication to maintain persistent access. Additionally, implementing network segmentation and mandatory access controls can help limit the blast radius of successful attacks. Organizations should also conduct thorough security assessments of their Jenkins environments to identify other potential vulnerabilities in authentication and authorization systems, ensuring comprehensive protection against similar threats.