Comelit Multi-User Gateway for VIP System (model 1456B) firmware versions 2.9.1 and 2.10.0 fail to enforce server-side authorization on an administrative password-change function. An authenticated user level can invoke this function to overwrite the installer (administrator) account password.
The vendor does not consider this a defect and has stated it will not be fixed, so the device's built-in role separation cannot be relied upon. As a mitigation, treat every account on the device as an administrator-equivalent account. Additionally, restrict network access to the device management interface to trusted administrators only.