The 3Com 3CRWER100-75 router with 1.2.10ww software, when enabling an optional virtual server, configures this server to accept all source IP addresses on the external (Internet) interface unless the user selects other options, which might expose the router to unintended incoming traffic from remote attackers, as demonstrated by setting up a virtual server on port 80, which allows remote attackers to access the web management interface.