A vulnerability in the Cisco Discovery Protocol of Cisco Unified Communications Manager (Unified CM) and Cisco Unified Communications Manager Session Management Edition (Unified CM SME) could allow an unauthenticated, adjacent attacker to cause a kernel panic on an affected system, resulting in a denial of service (DoS) condition. This vulnerability is due to incorrect processing of certain Cisco Discovery Protocol packets. An attacker could exploit this vulnerability by continuously sending certain Cisco Discovery Protocol packets to an affected device. A successful exploit could allow the attacker to cause a kernel panic on the system that is running the affected software, resulting in a DoS condition.
https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-ucm-dos-zHS9X9kD