Multiple TP-Link Wi-Fi range extenders use a custom, reversible XOR-and-dictionary transformation in the HTTP web-management login flow. An unauthenticated attacker on the same local network who can capture the network traffic associated with legitimate administrator login may be able to derive an alternative credential value that produces the same accepted authentication result and use it to authenticate to the device’s web-management interface with administrator privileges. Exploitation requires the management login to use HTTP and the attacker to observe the session key, dictionary, and login value associated with a legitimate administrator login. Successful exploitation may allow an unauthenticated adjacent attacker to gain administrator access to the affected device and modify exposed configuration settings.