If you want to run a business with a website, security must be high on your list of important matters to get right up front. In this article, you will learn about Internet-based network security assessment and penetration testing, which can help you determine your website's risk of being successfully attacked -- and what to do to fix any problems. It is taken from chapter one of the book Network Security Assessment by Chris McNab (O'Reilly, 2004; ISBN: 059600611X).
Assessment of large networks in particular can become a very cyclic process if you are testing the networks of an organization in a blind sense and are given minimal information. As you test the network, information leak bugs can be abused to find different types of useful information (including trusted domain names, IP address blocks, and user account details) that is then fed back into other processes. Figure 1-2ís flowchart defines this approach and the data being passed between processes.
This flowchart starts with network enumeration, then bulk network scanning, and finally specific service assessment. It may be the case that by assessing a rogue non-authoritative DNS service an analyst may identify previously unknown IP address blocks, which can be fed back into the network enumeration process to identify further network components. In the same way, an analyst may enumerate a number
Figure 1-2.The cyclic approach to network security assessment
of account usernames by exploiting public folder information leak vulnerabilities in Microsoft Outlook Web Access, which can be fed into a brute-force password grinding process later on.