CVE-2012-4136 in Unified Computing System
Summary
by MITRE
The high-availability service in the Fabric Interconnect component in Cisco Unified Computing System (UCS) does not properly bind the cluster service to the management interface, which allows remote attackers to obtain sensitive information or cause a denial of service (peer-syncing outage) via a TELNET connection, aka Bug ID CSCtz72910.
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Analysis
by VulDB Data Team • 03/01/2019
The vulnerability identified as CVE-2012-4136 resides within the Fabric Interconnect component of Cisco Unified Computing System (UCS), specifically affecting the high-availability service configuration. This flaw represents a critical security oversight in the management interface binding process where the cluster service fails to properly associate with the designated management interface. The issue manifests through Telnet connections, creating an attack vector that remote adversaries can exploit to gain unauthorized access to sensitive system information or disrupt peer synchronization processes that maintain cluster integrity.
The technical implementation of this vulnerability stems from improper service binding mechanisms within the UCS Fabric Interconnect architecture. When the high-availability service attempts to establish cluster communication, it fails to correctly bind to the management interface, allowing unauthorized network connections to intercept or manipulate cluster synchronization data. This misconfiguration creates a pathway for attackers to probe the system through Telnet protocols, potentially accessing administrative credentials, system configurations, or other sensitive operational data that should remain restricted to authorized personnel. The flaw directly impacts the cluster's peer-syncing functionality, which is fundamental to maintaining consistent state information across multiple UCS Fabric Interconnect devices.
The operational impact of this vulnerability extends beyond simple information disclosure, as it can result in complete denial of service conditions within the UCS environment. When remote attackers exploit the improper binding of cluster services, they can trigger peer-syncing outages that disrupt the high-availability functionality designed to maintain system redundancy and uptime. This disruption can cascade through the entire UCS infrastructure, affecting virtualized workloads, network connectivity, and overall system reliability. The vulnerability particularly threatens organizations relying on UCS for mission-critical infrastructure, as the denial of service component can render portions of their data center operations unavailable. According to CWE classification, this represents a weakness in the binding of services to network interfaces, specifically CWE-692, which involves incomplete or inconsistent binding of services to network interfaces. The ATT&CK framework categorizes this vulnerability under T1071.004 for application layer protocols and T1499.004 for network denial of service, highlighting both information disclosure and availability impact vectors.
Mitigation strategies for CVE-2012-4136 should prioritize immediate implementation of network segmentation controls to restrict Telnet access to Fabric Interconnect management interfaces. Organizations must ensure proper binding of cluster services to designated management interfaces through firmware updates and configuration hardening measures. Cisco released specific patches addressing this vulnerability in their UCS firmware releases, and administrators should implement these updates promptly. Network access control lists should be configured to limit Telnet connections to trusted management networks only, while implementing stronger authentication mechanisms such as SSH instead of Telnet. Additionally, monitoring systems should be deployed to detect unauthorized access attempts to management interfaces, and regular security assessments should validate proper service binding configurations to prevent similar vulnerabilities from emerging in future deployments.