CVE-2006-1973 in RT31P2
Summary
by MITRE
Multiple unspecified vulnerabilities in Linksys RT31P2 VoIP router allow remote attackers to cause a denial of service via malformed Session Initiation Protocol (SIP) messages.
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Analysis
by VulDB Data Team • 11/24/2024
The CVE-2006-1973 vulnerability affects the Linksys RT31P2 VoIP router, a device that serves as a critical component in voice over internet protocol communications. This router implements SIP protocol handling for managing voice calls and multimedia sessions, making it a potential target for malicious actors seeking to disrupt communication services. The vulnerability manifests through insufficient input validation mechanisms within the router's SIP message processing capabilities, creating a pathway for remote exploitation without requiring authentication or privileged access. The affected device operates at the network infrastructure level where SIP signaling occurs, positioning it as a prime target for denial of service attacks that can impact business continuity and emergency communication services.
The technical flaw resides in the router's failure to properly validate and sanitize incoming SIP messages, specifically when processing malformed or crafted SIP packets. This lack of input sanitization creates a condition where specially constructed SIP messages can cause the router's SIP processing module to crash or become unresponsive, leading to a complete denial of service state. The vulnerability operates at the application layer of the network stack, targeting the SIP protocol implementation within the router's firmware. Attackers can exploit this weakness by sending malformed SIP messages that trigger buffer overflows, invalid state transitions, or other processing errors within the router's SIP handling code, causing the device to restart or become unresponsive to legitimate traffic.
The operational impact of this vulnerability extends beyond simple service disruption, as VoIP routers serve critical communication functions in both enterprise and residential environments. When exploited, the denial of service condition can interrupt voice communications, potentially affecting emergency services, business operations, and personal communication channels. The remote nature of the attack means that adversaries can target these devices from anywhere on the internet without requiring physical access or network proximity. This vulnerability particularly impacts organizations that rely on VoIP infrastructure for business continuity, as the disruption can cascade to affect customer service operations, internal communications, and collaboration systems. The attack surface is further expanded due to the widespread deployment of similar Linksys VoIP router models, making this a scalable threat across multiple network environments.
Mitigation strategies for CVE-2006-1973 should focus on implementing network segmentation and access control measures to limit exposure of VoIP infrastructure to untrusted networks. Organizations should deploy network monitoring tools to detect anomalous SIP traffic patterns that may indicate exploitation attempts, and implement rate limiting or filtering mechanisms at network perimeters to prevent malformed SIP messages from reaching vulnerable devices. Firmware updates and patches from Linksys should be applied immediately to address the underlying validation issues within the SIP processing code, though the age of this vulnerability suggests that such updates may no longer be available for this specific model. Network administrators should also consider implementing intrusion detection systems that can identify and block suspicious SIP traffic patterns, while maintaining detailed logging of SIP communications for forensic analysis. This vulnerability aligns with CWE-129, which addresses improper validation of input boundaries, and maps to ATT&CK technique T1499.004 for network denial of service attacks, emphasizing the importance of protecting critical communication infrastructure from remote exploitation.