An issue was discovered on Mercusys MW325R EU V3 MW325R(EU)_V3_1.11.0 221019 devices. A WAN attacker can make the admin interface unreachable/invisible via an unauthenticated HTTP request. Verification of the data sent by the user does not occur. The web server does not crash, but the admin interface becomes invisible, because the files necessary to display the content are no longer available. A reboot of the router is typically required to restore the correct behavior.