CVE-2012-4079 in Unified Computing System
Summary
by MITRE
The XML API service in the Fabric Interconnect component in Cisco Unified Computing System (UCS) allows remote attackers to cause a denial of service (API service outage) via a malformed XML document in a packet, aka Bug ID CSCtg48206.
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Analysis
by VulDB Data Team • 03/01/2019
The vulnerability identified as CVE-2012-4079 represents a critical denial of service flaw within the Fabric Interconnect component of Cisco Unified Computing System. This issue specifically affects the XML API service which serves as a communication interface for managing and configuring the unified computing infrastructure. The vulnerability stems from insufficient input validation mechanisms that fail to properly process malformed XML documents, creating a pathway for remote attackers to disrupt critical system operations. The Fabric Interconnect serves as a central management point for UCS domains, making this vulnerability particularly dangerous as it can compromise the entire unified computing environment's availability and operational integrity.
The technical flaw manifests when the XML API service receives a malformed XML document in network packets, causing the service to crash or become unresponsive. This occurs due to inadequate parsing and validation routines that do not adequately sanitize incoming XML data before processing. The vulnerability falls under CWE-20, which categorizes improper input validation as a fundamental weakness in software design. When attackers exploit this flaw, they can send specially crafted XML packets that trigger buffer overflows, memory corruption, or other parsing failures within the API service. The malformed XML documents exploit weaknesses in the XML parser implementation, leading to unexpected behavior that results in complete service outages rather than merely degraded performance.
The operational impact of CVE-2012-4079 extends beyond simple service disruption, as it can severely compromise the availability of critical infrastructure management functions within Cisco UCS environments. Organizations relying on UCS for data center operations face potential business disruption when this vulnerability is exploited, as the Fabric Interconnect's API service outage affects the ability to configure, monitor, and manage the entire UCS domain. This vulnerability directly impacts the availability component of the CIA triad, potentially affecting mission-critical applications that depend on stable UCS infrastructure. The attack vector is particularly concerning as it requires no authentication, making it accessible to any remote attacker with network connectivity to the affected system. This characteristic aligns with ATT&CK technique T1499.004, which involves network denial of service attacks targeting infrastructure components.
Mitigation strategies for CVE-2012-4079 should focus on implementing robust input validation and access control measures for the XML API service. Network administrators should apply the latest Cisco security patches and firmware updates that address this specific vulnerability, as these releases typically include enhanced XML parsing routines and improved error handling mechanisms. Implementing network segmentation and access control lists can help limit exposure by restricting direct access to the Fabric Interconnect API service from untrusted networks. Additionally, deploying intrusion detection systems with signature-based detection for known malformed XML patterns can provide early warning of exploitation attempts. Organizations should also consider implementing monitoring solutions that can detect unusual API service behavior or connection patterns that may indicate exploitation attempts. The remediation process must include comprehensive testing of patched systems to ensure that the vulnerability is fully resolved without introducing new operational issues, particularly in complex UCS environments where multiple interdependent components may be affected by the update process.