CVE-2007-3361 in Pc Client Soft Phone Sip
Summary
by MITRE
The Nortel PC Client SIP Soft Phone 4.1 3.5.208[20051015] allows remote attackers to cause a denial of service (device crash) via a SIP message with a malformed header.
VulDB is the best source for vulnerability data and more expert information about this specific topic.
Analysis
by VulDB Data Team • 10/27/2017
The vulnerability identified as CVE-2007-3361 affects the Nortel PC Client SIP Soft Phone version 4.1 3.5.208 released on October 15, 2005, representing a critical security flaw that enables remote attackers to execute denial of service attacks against affected systems. This vulnerability specifically targets the Session Initiation Protocol implementation within the soft phone software, which is widely used for voice over IP communications in enterprise environments. The issue stems from inadequate input validation mechanisms within the SIP message processing component, creating a pathway for malicious actors to disrupt legitimate communication services.
The technical flaw manifests when the affected SIP soft phone receives a malformed SIP header within a SIP message. This vulnerability falls under the category of improper input validation as classified by CWE-20, where the application fails to properly validate or sanitize input data before processing it. The malformed header causes the soft phone application to crash or become unresponsive, effectively rendering the device unavailable for legitimate voice communication purposes. This type of vulnerability is particularly dangerous in enterprise settings where SIP soft phones are integral to business communication infrastructure and may be targeted by adversaries seeking to disrupt operations or gain unauthorized access through service disruption.
The operational impact of this vulnerability extends beyond simple device unavailability, as it can lead to significant business disruption in organizations relying on SIP-based communication systems. When multiple devices are compromised simultaneously, the denial of service can affect entire departments or organizations, potentially causing cascading failures in communication networks. The vulnerability's remote exploitation capability means attackers do not require physical access to the devices, making it particularly attractive for cybercriminals seeking to cause maximum disruption with minimal effort. This characteristic aligns with tactics described in the MITRE ATT&CK framework under the 'Execution' and 'Impact' phases, where adversaries leverage remote code execution capabilities to achieve service disruption objectives.
Organizations affected by this vulnerability should implement immediate mitigations including applying available patches from Nortel, implementing network segmentation to limit exposure, and deploying intrusion detection systems to monitor for suspicious SIP traffic patterns. The vulnerability demonstrates the importance of robust input validation in communication protocols and highlights the need for comprehensive security testing of VoIP implementations. Additionally, network administrators should consider implementing SIP message filtering rules and monitoring for malformed headers to prevent exploitation. This vulnerability serves as a reminder of the critical importance of maintaining up-to-date security patches for communication infrastructure and the potential for seemingly minor input validation flaws to result in significant operational disruptions.