CVE-2016-1346 in TelePresence Server
Summary
by MITRE
The kernel in Cisco TelePresence Server 3.0 through 4.2(4.18) on Mobility Services Engine (MSE) 8710 devices allows remote attackers to cause a denial of service (panic and reboot) via a crafted sequence of IPv6 packets, aka Bug ID CSCuu46673.
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Analysis
by VulDB Data Team • 07/12/2022
The vulnerability identified as CVE-2016-1346 represents a critical denial of service flaw within the kernel of Cisco TelePresence Server software running on Mobility Services Engine 8710 devices. This vulnerability specifically affects versions 3.0 through 4.2(4.18) and demonstrates how improperly handled network protocols can lead to system instability and complete service disruption. The flaw resides in the kernel's processing of IPv6 packets, where an attacker can exploit a specific sequence of malformed packets to trigger a kernel panic that results in system reboot. This type of vulnerability falls under the category of kernel-level denial of service attacks that can have severe operational consequences for organizations relying on telepresence infrastructure for critical communications.
The technical implementation of this vulnerability involves the kernel's insufficient validation of IPv6 packet sequences, particularly when processing certain combinations of IPv6 headers and payload data. When the affected system receives a crafted sequence of IPv6 packets, the kernel's networking stack fails to properly handle the malformed data structures, leading to a kernel panic condition. This panic causes the operating system to terminate unexpectedly and initiate a system reboot as a protective measure against further corruption. The vulnerability is particularly concerning because it requires minimal network access to exploit, making it highly accessible to remote attackers who can leverage it from outside the network perimeter. According to CWE classification, this vulnerability maps to CWE-129: Improper Validation of Array Index, as the kernel fails to properly validate packet data boundaries during IPv6 processing, and potentially CWE-122: Heap Overflow, when dealing with malformed packet structures that exceed expected buffer sizes.
The operational impact of CVE-2016-1346 extends far beyond simple service interruption, as it can severely disrupt business continuity for organizations relying on telepresence systems for critical communications including video conferencing, remote collaboration, and distance learning applications. The automatic reboot cycle can last several minutes, during which time critical business operations that depend on these systems are completely unavailable. This vulnerability particularly affects enterprises using Cisco's TelePresence solutions in mission-critical environments where uptime is essential for maintaining operational efficiency. Organizations may experience cascading effects when such systems fail, as they often integrate with other communication platforms, calendar systems, and collaboration tools that depend on stable telepresence infrastructure. The vulnerability also poses challenges for network security operations since the attack can be executed remotely without requiring authentication credentials, making it particularly dangerous in environments where network segmentation is not properly implemented.
Mitigation strategies for this vulnerability should include immediate implementation of Cisco's security advisories and patches released for affected versions of the TelePresence Server software. Network administrators should prioritize applying the vendor-provided firmware updates that address the kernel-level packet validation issues. Additionally, implementing network access controls and firewall rules that restrict IPv6 traffic to only necessary sources can provide temporary protection while patches are deployed. The implementation of intrusion detection systems that monitor for unusual IPv6 packet sequences may help detect exploitation attempts before they succeed. Organizations should also consider implementing network segmentation to isolate telepresence systems from critical network infrastructure, thereby limiting the potential impact of successful exploitation. From an ATT&CK framework perspective, this vulnerability aligns with techniques such as T1499.004: Endpoint Denial of Service and T1071.004: Application Layer Protocol: DNS, as attackers can leverage the vulnerability to disrupt services while potentially using DNS for reconnaissance or command and control communications. Regular network monitoring and vulnerability assessment procedures should be enhanced to detect similar kernel-level flaws in other network infrastructure components, as this type of vulnerability often indicates broader system exposure to similar attack vectors.