Gray Hat Hacking, Second Edition, 2nd Edition

Mitigation Alternatives

More than enough resources are available that discuss the basics of network and application security. This chapter does not aim to enumerate all of the time-tested methods of securing computer systems. However, given the current state of the art in defensive techniques, we must emphasize that it remains difficult if not impossible to defend against a zero-day attack. When new vulnerabilities are discovered, we can only defend against them if we can prevent attackers from reaching the vulnerable application. All of the standard risk assessment questions should be revisited:

• Is this service really necessary? If not, turn it off.

• Should it be publicly accessible? If not, firewall it.

• Are all unsafe options turned off? If not, ...