So can anyone propose a sane way to check devices for vulnerability? Obviously one can disable NetUSB in the web interface, but that may not be enough. Nmaping

So can anyone propose a sane way to check devices for vulnerability? Obviously one can disable NetUSB in the web interface, but that may not be enough. Nmaping port 20005 is not accurate enough. I want to check 3 of my routers, both from LAN and WAN.