FutureNet NXR series routers provided by Century Systems Co., Ltd. have REST-APIs, which are configured as disabled in the initial (factory default) configuration. But, REST-APIs are unexpectedly enabled when the affected product is powered up, provided either http-server (GUI) or Web authentication is enabled. The factory default configuration makes http-server (GUI) enabled, which means REST-APIs are also enabled. The username and the password for REST-APIs are configured in the factory default configuration. As a result, an attacker may obtain and/or alter the affected product's settings via REST-APIs.