Bugtraq: conexant adsl router backdoor

[Luca Bartolomai <mefistofle () libero it>]

Hi ,
I have acquired one router adsl conexant model Trident .
This modem is identical to the Italian version Digicom Michelangelo Office, 
but the firmware is modding .
If get file CONFIG.REG from ftp modem server and edit it , you can see this 
DWORD :
[Class\Protocol\Bridge\0000]
"DeviceId"=dword:00000000
"BackDoorEnabled"=dword:00000001
"EthernetFilterEnabled"=dword:00000000
"OutputProcessingEnabled"=dword:00000000
"SubnetMuxEnabled"=dword:00000001

BackDoorEnabled ?  what is ?

I'am scaned with nmap but not found particular listen port .
it is a backdoor on ATM ?
I will continue to inquire 

Best regards 

Jack