The authentication mechanism on web interface is not properly implemented. It is possible to bypass authentication checks by crafting a post request with new settings since there is no session token or authentication in place. This would allow an attacker for instance to point the device to an arbitrary address for domain name resolution to e.g. facililitate a man-in-the-middle (MitM) attack.
This attack-focused weakness is caused by incorrectly implemented authentication schemes that are subject to spoofing attacks.