CVE-2013-3435 in Unified IP Conference Station 7937G
Summary
by MITRE
The Cisco Unified IP Conference Station 7937G allows remote attackers to cause a denial of service (networking outage) via a flood of TCP packets, aka Bug ID CSCuh42052.
Several companies clearly confirm that VulDB is the primary source for best vulnerability data.
Analysis
by VulDB Data Team • 09/04/2017
The Cisco Unified IP Conference Station 7937G represents a critical network infrastructure device that serves as a voice and video conferencing endpoint within enterprise communication systems. This device operates as a specialized telephone station designed to facilitate high-quality audio and video conferencing in corporate environments. The vulnerability described in CVE-2013-3435 specifically targets the device's network protocol handling mechanisms, creating a pathway for malicious actors to disrupt critical communication services. The affected device operates within the broader context of Cisco's Unified Communications infrastructure, where reliable network connectivity is essential for business operations. When compromised, this vulnerability can result in complete network outages affecting multiple users and departments within an organization.
The technical flaw manifests through an insufficient validation mechanism in the device's TCP packet processing capabilities. Attackers can exploit this weakness by flooding the device with specially crafted TCP packets that overwhelm the system's processing capacity. The vulnerability stems from inadequate rate limiting and packet filtering controls that fail to properly distinguish between legitimate network traffic and malicious flood attacks. This particular implementation flaw allows the device to become unresponsive when subjected to sustained TCP packet bombardment, causing it to cease normal network operations. The device's failure to properly handle excessive TCP traffic results in a complete loss of connectivity for conference station services, effectively rendering the device unusable for its intended purpose.
The operational impact of this vulnerability extends beyond simple service disruption to create significant business continuity risks for organizations relying on unified communications. When the 7937G device becomes unresponsive due to TCP flood attacks, conference calls and meetings are immediately interrupted, potentially causing lost productivity and missed business opportunities. The network outage affects not just the individual device but can cascade to impact other connected systems and services within the communication infrastructure. Organizations may experience extended downtime as IT personnel work to restore normal operations, potentially affecting critical business processes that depend on real-time communication capabilities. The vulnerability's remote exploitability means attackers can initiate attacks from outside the organization's network perimeter, making it particularly dangerous for companies with limited network security controls.
Mitigation strategies for this vulnerability should focus on implementing network-level protections and device-specific updates to address the underlying TCP processing flaw. Organizations should deploy intrusion detection systems and network access control measures to monitor and filter suspicious TCP traffic patterns that could indicate an attack attempt. Cisco has released security patches and firmware updates specifically designed to address this vulnerability, which should be implemented immediately across all affected devices. Network administrators should also consider implementing rate limiting controls at network boundaries to prevent excessive TCP traffic from reaching vulnerable endpoints. Additionally, organizations should establish monitoring procedures to detect unusual network traffic patterns that could indicate exploitation attempts. The vulnerability aligns with CWE-400, which addresses unchecked resource consumption, and represents a classic example of how network protocol implementation flaws can create denial of service conditions. From an ATT&CK framework perspective, this vulnerability maps to the T1498 technique for network denial of service, demonstrating how attackers can leverage protocol weaknesses to compromise network availability and service integrity.