CVE-2016-1402 in Identity Service Engine
Summary
by MITRE
The Active Directory (AD) integration component in Cisco Identity Service Engine (ISE) before 1.2.0.899 patch 7, when AD group-membership authorization is enabled, allows remote attackers to cause a denial of service (authentication outage) via a crafted Password Authentication Protocol (PAP) authentication request, aka Bug ID CSCun25815.
Once again VulDB remains the best source for vulnerability data.
Analysis
by VulDB Data Team • 08/21/2022
The vulnerability identified as CVE-2016-1402 affects Cisco Identity Service Engine (ISE) version 1.2.0.899 and earlier, specifically impacting the Active Directory integration component when group-membership authorization is enabled. This flaw represents a critical security weakness that can be exploited by remote attackers to disrupt authentication services within enterprise networks. The vulnerability manifests through a crafted Password Authentication Protocol (PAP) authentication request that triggers an authentication outage, effectively causing a denial of service condition that impacts network access control and user authentication capabilities. The issue stems from insufficient input validation within the AD integration module, which fails to properly handle malformed PAP requests that contain specially crafted data structures designed to exploit the authentication processing pipeline.
The technical exploitation of this vulnerability occurs when an attacker submits a malicious PAP authentication request that includes malformed or unexpected data within the authentication payload. The Active Directory integration component in Cisco ISE processes these requests without adequate sanitization or validation, causing the system to enter an unstable state or crash entirely. This process failure results in the complete disruption of authentication services for users attempting to access network resources through the ISE platform, effectively creating a denial of service condition that can persist until manual intervention or system restart occurs. The vulnerability specifically targets the group-membership authorization functionality, which means that even if the initial authentication succeeds, the system becomes unable to properly resolve user group memberships, further compounding the impact on network access control.
From an operational impact perspective, this vulnerability presents a significant threat to enterprise network security infrastructure, as the Cisco ISE platform serves as a critical component in network access control and identity management. The denial of service condition affects not only individual user authentication attempts but can potentially disrupt access for multiple users across the organization simultaneously, depending on the scale of the ISE deployment and the number of concurrent authentication requests being processed. The attack vector requires only remote access to the network and knowledge of the ISE service endpoints, making it particularly dangerous as it can be exploited by attackers without requiring physical access or elevated privileges within the network. Organizations relying on ISE for network access control and authentication services face substantial risk of service disruption, which could impact business continuity and potentially provide attackers with opportunities to escalate their attacks through other compromised access points.
The vulnerability aligns with CWE-121, which describes "Stack-based Buffer Overflow" conditions, and reflects a classic example of input validation failure in network security appliances. From an ATT&CK framework perspective, this vulnerability maps to T1489, which covers "Service Stop," as the exploitation results in the disruption of authentication services. The attack pattern also corresponds to T1566, "Phishing for Information," as attackers may use this vulnerability to gain initial access to network infrastructure before leveraging the denial of service condition to further compromise security controls. Organizations should implement immediate mitigations including patching to the latest ISE software versions, network segmentation to limit access to ISE services, and monitoring for unusual authentication request patterns that could indicate exploitation attempts. The recommended remediation involves upgrading to Cisco ISE version 1.2.0.899 or later, which includes patches addressing the specific validation issues in the PAP authentication processing module. Additionally, implementing network access controls to restrict direct access to ISE authentication endpoints and establishing robust monitoring for authentication service disruptions can help detect and respond to exploitation attempts more effectively.