CVE-2017-3808 in Unified Communications Manager
Summary
by MITRE
A vulnerability in the Session Initiation Protocol (SIP) UDP throttling process of Cisco Unified Communications Manager (Cisco Unified CM) could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. The vulnerability is due to insufficient rate limiting protection. An attacker could exploit this vulnerability by sending the affected device a high rate of SIP messages. An exploit could allow the attacker to cause the device to reload unexpectedly. The device and services will restart automatically. This vulnerability affects Cisco Unified Communications Manager (CallManager) releases prior to the first fixed release; the following list indicates the first minor release that includes the fix for this vulnerability: 10.5.2.14900-16 11.0.1.23900-5 11.5.1.12900-2. Cisco Bug IDs: CSCuz72455.
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Analysis
by VulDB Data Team • 08/28/2024
The vulnerability described in CVE-2017-3808 represents a critical denial of service weakness within Cisco Unified Communications Manager's Session Initiation Protocol implementation. This flaw specifically targets the UDP throttling mechanisms that govern how the system handles incoming SIP traffic, creating an avenue for remote attackers to disrupt normal communication services. The vulnerability stems from inadequate rate limiting controls that fail to properly monitor and regulate the volume of SIP messages processed by the affected system, making it susceptible to exploitation through carefully crafted traffic patterns.
The technical exploitation of this vulnerability occurs when an unauthenticated remote attacker floods the targeted Cisco Unified CM device with an excessive rate of SIP messages. This deliberate overload overwhelms the system's ability to process legitimate communications while maintaining adequate resource allocation. The insufficient rate limiting protection allows these malicious traffic patterns to bypass normal traffic management controls, leading to system instability and ultimately forcing the device to undergo unexpected reload cycles. The vulnerability specifically affects Cisco Unified CM releases prior to version 10.5.2.14900-16, 11.0.1.23900-5, and 11.5.1.12900-2, indicating that proper mitigation was implemented in these subsequent releases.
From an operational impact perspective, this vulnerability poses significant risks to enterprise communication infrastructures that rely on Cisco Unified CM for voice and video services. The automatic device reloads and service restarts caused by exploitation create substantial downtime for critical business communications, potentially affecting thousands of users simultaneously. The DoS condition effectively renders the communication system unavailable until automatic recovery occurs, disrupting business continuity and potentially leading to financial losses. Organizations utilizing affected versions face the risk of prolonged service interruptions that can cascade across their entire communication network infrastructure.
The vulnerability aligns with CWE-770, which addresses the allocation of resources without proper limits or throttling mechanisms, and represents a classic example of inadequate input validation and resource management in network protocol implementations. From an ATT&CK framework perspective, this vulnerability maps to the T1499.004 technique related to network denial of service, where adversaries leverage protocol weaknesses to exhaust system resources and cause service disruption. The attack vector is particularly concerning as it requires no authentication credentials, making it accessible to any remote actor with network connectivity to the affected system.
Organizations should prioritize immediate remediation by upgrading to the fixed releases mentioned in the vulnerability advisory, specifically versions 10.5.2.14900-16, 11.0.1.23900-5, and 11.5.1.12900-2. Network administrators should also implement additional monitoring controls to detect unusual SIP traffic patterns that might indicate attempted exploitation. While waiting for official patches, temporary mitigations could include implementing network-level rate limiting for SIP traffic or deploying intrusion detection systems capable of identifying abnormal SIP message rates. The vulnerability highlights the importance of proper resource management and rate limiting in critical communication infrastructure components, emphasizing the need for comprehensive security testing of protocol implementations before deployment in production environments.