The web application does not sufficiently verify inputs that are assumed to be immutable but are actually externally controllable. A low-privileged user can modify the parameters and potentially manipulate account-level privileges.
Shenzhen Tenda W30E V2 firmware versions up to and including V16.01.0.19(5037) allow account passwords to be changed through the maintenance interface without requiring verification of the existing password. This enables unauthorized password changes when access to the affected endpoint is obtained.