A vulnerability in the change password functionality of Cisco Expressway Series and Cisco TelePresence Video Communication Server (VCS) could allow an authenticated, remote attacker with Read-only credentials to elevate privileges to Administrator on an affected system. This vulnerability is due to incorrect handling of password change requests. An attacker could exploit this vulnerability by authenticating to the application as a Read-only user and sending a crafted request to the web-based management interface. A successful exploit could allow the attacker to alter the passwords of any user on the system, including an administrative user, and then impersonate that user. Note: Cisco Expressway Series refers to the Expressway Control (Expressway-C) device and the Expressway Edge (Expressway-E) device.