Solutions in this Appendix:

• What Is a Vulnerability Assessment?

• Automated Assessments

• Two Approaches

• Realistic Expectations

• Summary

• Solutions Fast Track

• Frequently Asked Questions

Introduction

In the war zone that is the modern Internet, manually reviewing each networked system for security flaws is no longer feasible. Operating systems, applications, and network protocols have grown so complex over the last decade that it takes a dedicated security administrator to keep even a relatively small network shielded from attack.

Each technical advance brings wave after wave of security holes. A new protocol might result in dozens of actual implementations, each of which could contain exploitable programming errors. Logic errors, vendor-installed backdoors, and default configurations plague everything from modern operating systems to the simplest print server. Yesterday s viruses seem positively tame compared to the highly optimized Internet worms that continuously assault every system attached to the global Internet.

To combat these attacks, a network administrator needs the appropriate tools and knowledge to identify vulnerable systems and resolve their security problems before they can be exploited. One of the most powerful tools available today is the vulnerability assessment, and this appendix describes what it is, what it can provide you, and why you should be performing them as often as possible. Following this is an analysis of the different types of solutions available, the advantages of each, and the actual steps used by most tools during the assessment process. The next section describes two distinct approaches used by the current generation of assessment tools and how...