CVE-2012-3060 in Unity Connection
Summary
by MITRE
Cisco Unity Connection (UC) 8.6, 9.0, and 9.5 allows remote attackers to cause a denial of service (CPU consumption) via malformed UDP packets, aka Bug ID CSCtz76269.
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Analysis
by VulDB Data Team • 02/04/2018
Cisco Unity Connection versions 8.6, 9.0, and 9.5 contain a critical vulnerability that enables remote attackers to execute denial of service attacks through carefully crafted malformed UDP packets. This vulnerability specifically targets the Unified Communications platform's handling of incoming network traffic, creating a condition where the system consumes excessive CPU resources, ultimately leading to service disruption. The flaw stems from insufficient input validation within the UDP packet processing mechanisms, allowing malicious actors to exploit the system's failure to properly sanitize incoming network data. The vulnerability has been catalogued under the MITRE ATT&CK framework as part of the network denial of service technique, specifically categorized under the T1498 sub-technique for network denial of service. This weakness represents a classic example of insufficient validation or sanitization, which maps directly to CWE-20, the well-known weakness category for improper input validation. The impact of this vulnerability extends beyond simple service disruption as it can effectively render the entire Unity Connection service unavailable to legitimate users, potentially compromising business continuity and communication infrastructure. The attack vector requires only network access to the affected system, making it particularly dangerous as it can be exploited from remote locations without requiring physical access or authentication credentials. When exploited, the malformed UDP packets cause the system to enter a processing loop where CPU utilization spikes to 100% or near maximum levels, preventing the platform from handling legitimate communication traffic. This behavior aligns with the broader category of resource exhaustion attacks that fall under the ATT&CK framework's T1499 category for resource exhaustion. The vulnerability affects organizations that rely on Cisco Unity Connection for voice messaging and unified communications services, potentially impacting call handling, voicemail processing, and overall system performance. The specific Bug ID CSCtz76269 identifies this as a known issue within Cisco's internal tracking systems, indicating that the company was aware of the vulnerability and had documented its characteristics. Organizations using affected versions of Cisco Unity Connection should immediately implement mitigation strategies including network segmentation, firewall rules to block suspicious UDP traffic, and applying the relevant security patches provided by Cisco. The vulnerability demonstrates the importance of robust input validation in network services and highlights how seemingly minor implementation flaws can result in significant operational disruptions. System administrators should also consider implementing monitoring solutions that can detect unusual CPU utilization patterns and automatically alert security teams to potential exploitation attempts. This vulnerability serves as a reminder of the critical need for regular security assessments and patch management processes to protect against known vulnerabilities in enterprise communication systems.
The technical implementation of this vulnerability occurs at the network protocol level where the Unity Connection system fails to properly validate UDP packet headers and payload data before processing. When malformed UDP packets are received, the system's processing logic does not adequately check for valid packet structures, causing the application to attempt processing of invalid data in a manner that consumes significant computational resources. The vulnerability is particularly concerning because it operates at the transport layer of the network stack, where it can affect the core functionality of the communication platform. The CPU consumption occurs during the packet parsing phase where the system attempts to interpret malformed data structures, leading to inefficient processing loops or recursive operations that consume resources linearly with the number of malicious packets received. This behavior creates a cascading effect where the system becomes increasingly unresponsive as more packets are processed, eventually leading to complete service disruption. The attack can be executed with minimal resources and technical expertise, making it a popular target for both malicious actors and security researchers conducting penetration testing. Network administrators should note that this vulnerability can be difficult to detect through standard network monitoring tools as the malicious traffic may appear legitimate until the system begins to exhibit resource exhaustion symptoms. The specific nature of the vulnerability also means that traditional intrusion detection systems may not effectively identify the attack pattern, as it mimics normal network traffic characteristics while exploiting the underlying implementation flaw. Organizations should implement comprehensive network access controls that limit UDP traffic to only necessary services and ports, effectively reducing the attack surface for this particular vulnerability. The remediation process requires careful attention to ensure that the security patch does not introduce compatibility issues with existing network configurations or communication protocols. Security teams should also conduct thorough testing of the patched environment to verify that the vulnerability has been fully addressed and that normal system operations remain unaffected. This vulnerability underscores the critical importance of maintaining up-to-date security patches across all network infrastructure components, particularly those handling real-time communication services where availability is paramount. The incident also highlights the need for robust network monitoring and incident response procedures to quickly detect and mitigate such attacks before they can cause significant disruption to business operations.