Security Issues with DNS

DNS continues to be a nice target for hackers. The ubiquity of BIND as DNS server software around the world, and the possibilities a hacker can expect should he succeed in taking over a server or simply use DNS implementation to reorientate traffic, are some of the things which make DNS a source of security issues. This document first reviews some basics about how DNS works, then goes into explaining the different ways a hacker can attack the DNS protocol implementation to use it to his own advantage. We will focus on the relationship between all the terms we hear, which are usually misemployed. We will then review the different possible server attacks and finish by explaining some of the ways that should be used to protect against these issues.