CVE-2006-0179 in IP Phone
Summary
by MITRE
The Cisco IP Phone 7940 allows remote attackers to cause a denial of service (reboot) via a large amount of TCP SYN packets (syn flood) to arbitrary ports, as demonstrated to port 80.
Be aware that VulDB is the high quality source for vulnerability data.
Analysis
by VulDB Data Team • 01/01/2025
The vulnerability identified as CVE-2006-0179 affects the Cisco IP Phone 7940, a widely deployed VoIP endpoint device in enterprise communications environments. This device operates as a networked telephone system component that requires robust security measures to prevent unauthorized access and service disruption. The vulnerability manifests as a weakness in the device's TCP stack implementation, specifically in how it handles incoming connection requests. The affected Cisco IP Phone 7940 device lacks proper protection mechanisms against TCP SYN flood attacks, which represent a common form of denial of service assault targeting network infrastructure.
The technical flaw resides in the device's inability to properly manage TCP connection establishment requests, creating a condition where excessive SYN packets can overwhelm the device's resources and trigger an automatic system reboot. This occurs because the device does not implement adequate rate limiting or connection queue management for TCP SYN requests, allowing malicious actors to flood the system with connection attempts that consume available memory and processing resources. The vulnerability is particularly concerning because it can be exploited against any port on the device, with demonstration showing successful exploitation against port 80, which typically serves web-based management interfaces for network devices.
The operational impact of this vulnerability extends beyond simple service disruption to potentially compromise entire communication networks where these phones are deployed. When exploited, the denial of service condition forces the device to reboot, effectively removing it from service and disrupting voice communications for users connected to that specific phone. This creates cascading effects in enterprise environments where multiple IP phones may be interconnected through a common network infrastructure, potentially leading to widespread communication outages. The vulnerability is particularly dangerous in mission-critical environments where continuous communication availability is essential for business operations or emergency response systems.
Network security professionals should implement multiple layers of defense to mitigate this vulnerability, including network segmentation to isolate VoIP devices from general network traffic, implementation of rate limiting on TCP SYN requests at network boundaries, and deployment of intrusion prevention systems that can detect and block SYN flood patterns. The vulnerability aligns with CWE-400, which categorizes improper resource management as a fundamental weakness in software systems, and maps to ATT&CK technique T1499.004 for network denial of service attacks. Organizations should also consider implementing proper network monitoring and alerting systems to detect unusual traffic patterns that may indicate exploitation attempts, while ensuring that all network devices receive regular security updates and patches from vendors to address known vulnerabilities in their systems.