A vulnerability in the CLI of Cisco Firepower Threat Defense (FTD) Software could allow an authenticated, local attacker to execute arbitrary commands with root privileges on the underlying operating system of an affected device that is running in multi-instance mode. This vulnerability is due to insufficient validation of user-supplied command arguments. An attacker could exploit this vulnerability by submitting crafted input to the affected command. A successful exploit could allow the attacker to execute commands on the underlying operating system with root privileges.