CVE-2008-1155 in Network Admission Control
Summary
by MITRE
Cisco Network Admission Control (NAC) Appliance 3.5.x, 3.6.x before 3.6.4.4, 4.0.x before 4.0.6, and 4.1.x before 4.1.2 allows remote attackers to obtain the shared secret for the Clean Access Server (CAS) and Clean Access Manager (CAM) by sniffing error logs.
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Analysis
by VulDB Data Team • 08/08/2019
The vulnerability described in CVE-2008-1155 represents a critical security flaw in Cisco Network Admission Control appliances that affects versions 3.5.x through 4.1.x prior to specific patch releases. This issue stems from improper handling of error logging mechanisms within the Clean Access Server and Clean Access Manager components, creating an information disclosure vulnerability that can be exploited by remote attackers. The flaw specifically impacts the authentication and authorization processes that govern network access control, making it particularly dangerous for enterprise environments that rely on these appliances for network security enforcement.
The technical implementation of this vulnerability involves the insecure logging of sensitive authentication data within error messages generated by the Clean Access Server and Clean Access Manager components. When the NAC appliance encounters authentication failures or other operational errors, it logs diagnostic information that inadvertently includes the shared secret used for communication between the CAS and CAM modules. This shared secret serves as a critical cryptographic key for maintaining secure communication between the network access control components and is essential for proper authentication of network devices and users. The error logging mechanism fails to sanitize or redact this sensitive information, allowing attackers who can intercept network traffic or gain access to the error logs to extract these credentials.
The operational impact of this vulnerability extends beyond simple information disclosure, as the shared secret obtained through this attack vector can be used to compromise the entire network admission control infrastructure. Attackers who successfully extract these credentials can potentially impersonate legitimate CAS and CAM components, gain unauthorized access to network resources, and potentially escalate their privileges within the network. This vulnerability undermines the fundamental security model of the NAC appliance by exposing the cryptographic keys that protect the integrity of network access decisions. The attack can be executed remotely without requiring any special privileges or physical access to the network infrastructure, making it particularly dangerous for organizations that depend on centralized network access control.
The vulnerability aligns with CWE-200, which addresses information exposure, and represents a classic case of insecure logging practices that violate secure coding principles. From an adversarial perspective, this flaw maps directly to ATT&CK technique T1552.001 for credentials from password storage, as it provides attackers with legitimate authentication credentials that can be used to gain persistent access to network resources. Organizations using affected Cisco NAC appliance versions should immediately implement mitigation strategies including patching to the recommended versions, implementing network segmentation to limit access to error logging systems, and monitoring for unusual network traffic patterns that might indicate exploitation attempts. The vulnerability highlights the importance of proper input validation and output sanitization in security-critical applications, particularly those handling authentication credentials and cryptographic keys.