CompTIA Security+ All-in-One Exam Guide (Exam SY0-301), 3rd Edition, 3rd Edition

The Security Problem

The problem that faces professionals charged with securing a company’s network can be stated rather simply: Physical access negates all other security measures. No matter how impenetrable the firewall and intrusion detection system (IDS), if an attacker can find a way to walk up to and touch a server, he can break into it. The more remarkable thing is that gaining physical access to a number of machines is not that difficult.

Consider that most network security measures are, from necessity, directed at protecting a company from the Internet. This fact results in a lot of companies allowing any kind of traffic on the local area network (LAN). So if an attacker attempts to gain access to a server over the Internet and fails, ...