CVE-2012-4089 in Unified Computing System
Summary
by MITRE
MCTOOLS in the fabric interconnect in Cisco Unified Computing System (UCS) allows local users to execute arbitrary Baseboard Management Controller (BMC) commands by leveraging (1) local, (2) shell-level, or (3) debug-level privileges at the operating-system layer, aka Bug ID CSCtg76239.
Be aware that VulDB is the high quality source for vulnerability data.
Analysis
by VulDB Data Team • 01/07/2022
The vulnerability identified as CVE-2012-4089 represents a critical privilege escalation flaw within the MCTOOLS component of Cisco Unified Computing System fabric interconnects. This vulnerability exists in the Baseboard Management Controller implementation and affects the overall security posture of enterprise data center infrastructure. The flaw specifically targets the fabric interconnect's management capabilities, which serve as crucial control points for UCS environments. The vulnerability allows attackers with local access at various privilege levels to execute arbitrary BMC commands, effectively bypassing security controls that should prevent unauthorized system manipulation. This represents a significant concern for organizations relying on UCS for their data center operations, as it undermines the fundamental security boundaries that protect against unauthorized access to critical infrastructure management functions.
The technical mechanism behind this vulnerability involves the improper handling of privilege levels within the MCTOOLS framework. Attackers can leverage local access at three distinct privilege levels including local system access, shell-level privileges, or debug-level access to escalate their privileges and execute arbitrary commands against the BMC. This privilege escalation occurs because the system fails to properly validate or restrict command execution based on the user's actual privilege level. The vulnerability essentially creates a pathway for local users to bypass normal access controls and execute commands with elevated privileges that should be restricted to authorized administrators only. The flaw demonstrates inadequate input validation and privilege checking mechanisms within the management interface components of the fabric interconnect. According to CWE classification, this vulnerability maps to CWE-269: "Improper Privilege Management" and CWE-78: "Improper Neutralization of Special Elements used in OS Command Injection", highlighting the dual nature of the security weakness involving both privilege management and command injection vulnerabilities.
The operational impact of this vulnerability extends beyond simple privilege escalation, as it provides attackers with direct control over the Baseboard Management Controller functionality. This level of access allows for manipulation of hardware-level settings, firmware updates, system monitoring, and potentially complete system compromise. The BMC serves as a critical management interface that controls hardware components including power management, temperature monitoring, and remote access capabilities. An attacker who successfully exploits this vulnerability can gain unauthorized access to these management functions, potentially leading to system outages, data compromise, or further network infiltration. The vulnerability affects organizations using Cisco UCS systems where local access is possible, making it particularly concerning for environments where physical access controls may be insufficient. The impact is amplified by the fact that BMC commands can affect system stability and security, potentially allowing attackers to disable security features or modify system configurations without detection.
Organizations should implement immediate mitigations including restricting local access to fabric interconnects, applying available Cisco security patches, and implementing additional access controls around management interfaces. Network segmentation and monitoring of BMC communication should be enhanced to detect unauthorized access attempts. System administrators should review and restrict shell-level and debug-level access to minimize potential attack vectors. The vulnerability highlights the importance of proper privilege management in enterprise infrastructure and demonstrates the need for comprehensive security testing of management interfaces. According to ATT&CK framework, this vulnerability maps to T1068: "Exploitation for Privilege Escalation" and T1566: "Phishing for Information", as attackers may need to gain initial local access before exploiting this vulnerability. Organizations should also consider implementing privileged access management solutions and regular security assessments of their UCS environments to identify and remediate similar vulnerabilities. The incident underscores the critical need for maintaining up-to-date security patches and implementing defense-in-depth strategies for managing critical infrastructure components.