A vulnerability in the CLI of Cisco Unity Express could allow an authenticated, local attacker to inject arbitrary commands that are executed with root privileges. To exploit this vulnerability, an attacker would need valid administrator credentials. The vulnerability is due to improper input validation for certain CLI commands that are executed on a vulnerable system. An attacker could exploit this vulnerability by logging in to the system and sending crafted CLI commands. A successful exploit could allow the attacker to execute arbitrary commands on the underlying operating system and elevate privileges to root.