I haven't checked recently if they changed it, but MongoDB by default will, to my knowledge, bind to all network devices it can find, allow connections from all

I haven't checked recently if they changed it, but MongoDB by default will, to my knowledge, bind to all network devices it can find, allow connections from all possible sources, and allow any connection to it full write access to everything in it. So, uh, make sure your firewall let's ONLY known machines through to it, and check the manual how to enable authorization. Or better yet: Use a database that isn't designed to be goatse by default.