i was wondering about the fact that 80% of the people leave the router's password the default password , and therefore could be easily accessed and modified , but if a router is accessed the attacker wont do much , just some modifications to get it down , but i was sondering , could a router run a program , or open a specific port to host something (the router itself becomes the host no redirection) , if anyone has any info about that it would be great ...

hey bosh cash,
most routers can only reset simple stuff like password or ip config.
other routers can only be accessed by ISP's.

however once in a while you will come acress the off router that will allow you to add ip address's for routing, and so depending on how the dmz/net facing setup is for that company you *could add your ip range to have full access to their systems.
(*not advised)

scanning for port 23 again another bad idea i have found tho, you will get to ISPS main routers and other things that will display nassty banners of "GO AWAY UNAUTHORIZED USERS"