A vulnerability in the API subsystem of Cisco Unified Contact Center Express (Unified CCX) could allow an authenticated, remote attacker to change the availability state of any agent. The vulnerability is due to insufficient authorization enforcement on an affected system. An attacker could exploit this vulnerability by authenticating to an affected system with valid agent credentials and performing a specific API call with crafted input. A successful exploit could allow the attacker to change the availability state of an agent, potentially causing a denial of service condition.