CVE-2012-0376 in Unified Communications Manager
Summary
by MITRE
The voice-sipstack component in Cisco Unified Communications Manager (CUCM) 8.5 allows remote attackers to cause a denial of service (core dump) via vectors involving SIP messages that arrive after an upgrade, aka Bug ID CSCtj87367.
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Analysis
by VulDB Data Team • 01/16/2018
The vulnerability identified as CVE-2012-0376 resides within the voice-sipstack component of Cisco Unified Communications Manager version 8.5, representing a significant security weakness that enables remote attackers to execute denial of service attacks. This flaw specifically manifests when SIP messages are received by the system following a software upgrade process, creating a window of opportunity for malicious actors to exploit the system's handling of these particular message sequences. The vulnerability's classification as a denial of service issue indicates that successful exploitation results in the generation of core dump files, effectively crashing the affected system and rendering critical communication services unavailable to legitimate users.
The technical nature of this vulnerability stems from inadequate input validation and state management within the SIP message processing framework of the CUCM system. When the voice-sipstack component receives SIP messages that arrive after an upgrade operation, the system fails to properly handle the transition state between the upgrade process and normal message processing. This failure creates a condition where the system's memory management becomes corrupted, leading to the generation of core dump files that consume system resources and ultimately result in service disruption. The vulnerability specifically impacts the SIP stack's ability to maintain proper state information during upgrade transitions, causing the system to crash and require manual intervention for recovery.
From an operational perspective, this vulnerability presents a substantial risk to organizations relying on Cisco Unified Communications Manager for their voice infrastructure, as it can be exploited remotely without requiring authentication credentials. The timing aspect of the attack, which requires messages to arrive after an upgrade, suggests that the vulnerability is particularly dangerous during maintenance windows when system administrators might be performing routine upgrades. The resulting core dumps not only disrupt service availability but also generate significant system resource consumption that can affect overall network performance. Organizations using this version of CUCM face the potential for extended downtime, service interruptions, and increased operational overhead as administrators must respond to these attacks and restore system functionality.
The vulnerability aligns with CWE-129, which addresses improper validation of input boundaries, and demonstrates characteristics consistent with CWE-248, concerning exposure of a resource to the wrong sphere. From an ATT&CK framework perspective, this vulnerability maps to T1499.004, which covers network denial of service attacks, and T1566.002, involving spearphishing with social engineering techniques that could be used to trigger the attack during upgrade operations. Organizations should implement immediate mitigations including applying Cisco's security patches, implementing network segmentation to limit access to SIP ports, and establishing monitoring procedures to detect unusual SIP message patterns that might indicate exploitation attempts. Additionally, administrators should consider implementing rate limiting on SIP message processing and ensuring proper system hardening practices to reduce the attack surface. The vulnerability underscores the importance of proper state management during upgrade processes and highlights the need for comprehensive testing of system components after software modifications to prevent similar issues in the future.