[madrebel]

as long as there isnt anything else listening on those ports there isnt a problem. ill break it down

12203-06 are probably their challenge/listen ports

6667 is irc.....lamespy irc
3783 is roger wilco....again owned by lamespy
27/28/29900 are standard q3 ports

the last 2 im not sure about.

so unless you have something listening on these other ports there isnt a problem.

you could always dmz the box and use a software firewall too.

the security risk isnt that great....its a game server after all. hopefully you arent hosting it on production servers.