CVE-2012-2499 in AnyConnect Secure Mobility Client
Summary
by MITRE
The IPsec implementation in Cisco AnyConnect Secure Mobility Client 3.0 before 3.0.08057 does not verify the certificate name in an X.509 certificate, which allows man-in-the-middle attackers to spoof servers via a crafted certificate, aka Bug ID CSCtz26985.
If you want to get best quality of vulnerability data, you may have to visit VulDB.
Analysis
by VulDB Data Team • 04/29/2018
The vulnerability identified as CVE-2012-2499 represents a critical certificate validation flaw within Cisco AnyConnect Secure Mobility Client version 3.0 and earlier releases. This issue specifically affects the IPsec implementation where the client fails to properly verify the certificate name contained within X.509 certificates. The failure occurs during the authentication process when establishing secure connections through the AnyConnect client, creating a significant security gap that can be exploited by malicious actors. The vulnerability is particularly concerning because it undermines the fundamental trust model of secure communications by allowing unauthorized parties to present fraudulent certificates that appear legitimate to the client.
The technical flaw stems from the incomplete implementation of certificate validation procedures within the IPsec framework of the AnyConnect client. When a server presents an X.509 certificate during the authentication handshake, the client should verify that the certificate's subject name matches the expected server identity. However, this validation step is bypassed or improperly implemented in affected versions, allowing attackers to generate certificates with misleading subject names that can successfully authenticate the client. This represents a classic failure in certificate chain validation that aligns with CWE-295, which specifically addresses "Improper Certificate Validation." The vulnerability enables attackers to perform man-in-the-middle attacks by presenting certificates that contain names that do not match the target server, yet the client accepts them as valid due to the missing validation check.
The operational impact of this vulnerability extends beyond simple network security concerns to potentially compromise entire enterprise networks. An attacker positioned in the network path between the client and server can intercept communications and present a forged certificate that appears legitimate to the AnyConnect client. This allows the attacker to decrypt and potentially modify network traffic, access sensitive data, and establish unauthorized access to network resources. The vulnerability affects organizations relying on Cisco AnyConnect for remote access, particularly those using IPsec-based connections where certificate-based authentication is employed. According to ATT&CK framework, this vulnerability maps to T1566.001 (Phishing via Service) and T1041 (Exfiltration Over C2 Channel) as attackers can use this weakness to establish persistent access and exfiltrate data. The impact is particularly severe in environments where sensitive information is transmitted over the network, as the vulnerability can be exploited without requiring elevated privileges or specialized knowledge of the target network.
Organizations should implement immediate mitigations including upgrading to Cisco AnyConnect Secure Mobility Client version 3.0.08057 or later, which contains the necessary certificate validation fixes. Network administrators should also consider implementing additional monitoring measures to detect anomalous certificate usage patterns and establish certificate pinning policies where appropriate. The vulnerability demonstrates the critical importance of proper certificate validation in secure communication protocols and highlights the necessity of thorough security testing of cryptographic implementations. Organizations should conduct comprehensive vulnerability assessments to identify all instances of the affected software and ensure that all remote access solutions are properly updated. The fix implemented by Cisco addresses the core validation issue by ensuring that certificate subject names are properly verified against expected server identities, thereby restoring the intended security properties of the IPsec implementation.