Common
Internet-related security breaches:
nIP spoofing
Outsiders
obtain internal IP addresses, then use those addresses to pretend that they have authority to access your internal network from the Internet
nWhen a user Telnets or FTPs to your site over the Internet, his or her user ID and password will be transmitted in plain text
nCrackers may obtain information about your user ID from newsgroups, mailing lists, or forms filled out on the Web