A vulnerability in the user management functionality of Cisco Enterprise NFV Infrastructure Software (NFVIS) could allow an authenticated, remote attacker to perform a denial of service (DoS) attack against an affected system. The vulnerability is due to insufficient validation of user-provided input. An attacker could exploit this vulnerability by logging in with a highly privileged user account and performing a sequence of specific user management operations that interfere with the underlying operating system. A successful exploit could allow the attacker to permanently degrade the functionality of the affected system.