CVE-2012-4117 in Unified Computing System
Summary
by MITRE
The fabric-interconnect component in Cisco Unified Computing System (UCS) does not properly verify X.509 certificates, which allows man-in-the-middle attackers to watch SSL KVM video-channel traffic or modify this traffic via a crafted certificate, aka Bug ID CSCtr73033.
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Analysis
by VulDB Data Team • 03/01/2019
The vulnerability identified as CVE-2012-4117 affects the fabric-interconnect component within Cisco Unified Computing System environments, representing a critical security flaw in certificate validation mechanisms. This issue specifically targets the X.509 certificate verification process that occurs during SSL KVM video-channel communications, creating a pathway for malicious actors to exploit the system's trust model. The vulnerability stems from insufficient certificate validation procedures that fail to properly authenticate the legitimacy of digital certificates presented during secure communications. This weakness enables attackers to perform man-in-the-middle attacks against the KVM video channel traffic, which is typically used for remote server management and monitoring purposes. The affected Cisco UCS fabric-interconnect component serves as a critical networking element that connects various computing resources within the unified computing environment, making it a prime target for attackers seeking to compromise the security of enterprise data centers.
The technical flaw manifests in the improper validation of X.509 certificates during SSL/TLS handshakes, where the system fails to perform adequate certificate chain validation and trust verification. This weakness allows attackers to present fraudulent certificates that appear legitimate to the system, thereby bypassing the intended security controls. The vulnerability specifically impacts the SSL KVM video-channel traffic, which carries sensitive visual data from remote management sessions, including console access and system monitoring information. Attackers can leverage this flaw to either eavesdrop on the video channel communications or actively modify the transmitted data, potentially leading to unauthorized access to server management interfaces or manipulation of critical system information. The vulnerability is particularly concerning because it affects the core infrastructure components that govern how computing resources communicate and authenticate with each other within the unified computing environment.
The operational impact of CVE-2012-4117 extends beyond simple data interception, as it fundamentally undermines the security posture of Cisco UCS deployments by enabling active manipulation of management communications. Organizations utilizing Cisco Unified Computing Systems face significant risks including unauthorized access to server management interfaces, potential data breaches through manipulation of video channel content, and compromise of the entire unified computing infrastructure. The vulnerability affects the integrity and confidentiality of remote management sessions, which are critical for maintaining system availability and security in enterprise data centers. This weakness can be exploited to gain unauthorized access to sensitive system information, potentially leading to broader security incidents within the organization's computing environment. The impact is particularly severe given that KVM video channels are commonly used for critical system administration tasks, making this vulnerability a high-value target for attackers seeking persistent access to enterprise infrastructure.
Organizations should implement immediate mitigations including updating to Cisco's patched firmware versions that address the certificate validation weaknesses in the fabric-interconnect component. Network segmentation and additional monitoring of SSL/TLS communications can help detect anomalous certificate usage patterns that may indicate exploitation attempts. Security administrators should also consider implementing certificate pinning mechanisms where possible, and regularly audit certificate trust configurations within their UCS environments. The vulnerability aligns with CWE-295, which addresses "Improper Certificate Validation," and represents a specific instance of the broader category of SSL/TLS security flaws that attackers exploit to compromise secure communications. From an ATT&CK framework perspective, this vulnerability maps to techniques involving credential access and defense evasion, as attackers can use the compromised KVM channels to maintain persistent access to target systems while avoiding detection through legitimate management interfaces. Organizations should also review their overall certificate management policies and ensure proper certificate lifecycle management practices are in place to prevent similar vulnerabilities from emerging in other system components.