CVE-2021-37736 in ClearPass Policy Manager
Summary
by MITRE • 10/15/2021
A remote authentication bypass vulnerability was discovered in Aruba ClearPass Policy Manager version(s): ClearPass Policy Manager 6.10.x prior to 6.10.2 - - ClearPass Policy Manager 6.9.x prior to 6.9.7-HF1 - - ClearPass Policy Manager 6.8.x prior to 6.8.9-HF1. Aruba has released patches for ClearPass Policy Manager that address this security vulnerability.
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Analysis
by VulDB Data Team • 10/20/2021
The CVE-2021-37736 vulnerability represents a critical remote authentication bypass flaw affecting Aruba ClearPass Policy Manager across multiple version streams including 6.10.x prior to 6.10.2, 6.9.x prior to 6.9.7-HF1, and 6.8.x prior to 6.8.9-HF1. This vulnerability resides within the authentication mechanisms of the ClearPass Policy Manager, which serves as a central authentication, authorization, and accounting solution for enterprise networks. The flaw allows unauthenticated remote attackers to bypass the authentication process and gain administrative access to the system, potentially enabling them to manipulate network access policies, view sensitive user information, and compromise the entire network infrastructure. The vulnerability stems from improper input validation and authentication flow handling within the web interface components of the policy manager.
This authentication bypass vulnerability operates at the application layer and can be classified under CWE-287 which deals with improper authentication issues. The technical implementation flaw likely involves insufficient validation of authentication tokens or session management mechanisms that allow attackers to exploit specific API endpoints or web forms without proper credential verification. Attackers can leverage this vulnerability to perform administrative actions such as creating new user accounts, modifying existing policies, accessing network device configurations, and potentially establishing persistent access to the network. The impact extends beyond simple unauthorized access as it undermines the fundamental security posture of the entire network infrastructure that relies on ClearPass for policy enforcement.
The operational impact of CVE-2021-37736 is severe and multifaceted, particularly for organizations that depend on Aruba ClearPass for network access control. Successful exploitation could result in complete network compromise, unauthorized data access, and potential lateral movement within the enterprise environment. The vulnerability affects organizations across various sectors including healthcare, financial services, and government entities where network security is paramount. The attack surface is significant as ClearPass Policy Manager typically serves as a central hub for managing network access across multiple network segments, making it an attractive target for attackers seeking persistent access. Additionally, the vulnerability's remote nature means attackers can exploit it from anywhere on the internet without requiring physical access to the network.
Organizations should immediately implement the patches released by Aruba for ClearPass Policy Manager versions 6.10.2, 6.9.7-HF1, and 6.8.9-HF1 to remediate this vulnerability. Network segmentation should be implemented to isolate the ClearPass Policy Manager from critical network segments, and strict firewall rules should be enforced to limit access to the system. Monitoring and logging should be enhanced to detect unusual authentication patterns or unauthorized access attempts. The vulnerability aligns with ATT&CK technique T1078 which covers valid accounts and privilege escalation, making it particularly dangerous as it allows attackers to operate under seemingly legitimate administrative credentials. Security teams should also conduct thorough network assessments to identify any potential compromise and implement network behavior analysis tools to detect anomalous activities that may indicate exploitation attempts.