A vulnerability in the Session Initiation Protocol (SIP) of Cisco Expressway Series and Cisco TelePresence Video Communication Server (VCS) could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. The vulnerability is due to incorrect handling of incoming SIP traffic. An attacker could exploit this vulnerability by sending a series of SIP packets to an affected device. A successful exploit could allow the attacker to exhaust memory on an affected device, causing it to crash and leading to a DoS condition.

A vulnerability in the restricted shell of Cisco Expressway Series could allow an authenticated, local attacker to perform command injection attacks on the underlying operating system and elevate privileges to root. To exploit this vulnerability, the attacker must have Administrator-level credentials with read-write privileges on an affected device. This vulnerability is due to insufficient validation of user-supplied input. An attacker could exploit this vulnerability by submitting a series of crafted CLI commands. A successful exploit could allow the attacker to escape the restricted shell and gain root privileges on the underlying operating system of the affected device. Note: Cisco Expressway Series refers to Cisco Expressway Control (Expressway-C) devices and Cisco Expressway Edge (Expressway-E) devices.