Elementary Information Security, 3rd Edition

▶ 2.3 Buffer Overflows and the Morris Worm

In a perfect world, a computer should not crash or misbehave just because it is connected to a network and it receives the “wrong” data. The network software (the computer’s protocol process) should identify a badly formed message and discard it. In practice, network software may contain flaws that allow cleverly designed messages to crash the software (and perhaps the computer’s operating system) or that may provide an attack vector for an attacker.

A “back door” is an attack vector that lets the attacker take control of a computer through a network connection. In the film WarGames (1983), a teen computer enthusiast found a backdoor connection. The teen thought he had reached a computer games company; ...