In Huawei HiRouter-CD20-10 with the versions before 1.9.6 and WS5200-10 with the versions before 1.9.6, there is a plug-in signature bypass vulnerability due to insufficient plug-in verification. An attacker may tamper with a legitimate plug-in to build a malicious plug-in and trick users into installing it. Successful exploit could allow the attacker to obtain the root permission of the device and take full control over the device.