One of the most commonly exploited vulnerabilities is the buffer overflow. Buffer overflows occur when too much information can be written to a predefined memory buffer, causing a program to fail.

There are many tools that let hackers exploit this vulnerability, and knowing them will help you learn how to prevent their successful use on your systems.

One such tool is Digital Monkey's Buffer Syringe, a relatively simple, minimally documented tool that lets hackers exploit buffer overflows. In fact, Buffer Syringe includes several usage examples that make implementation of the tool a snap.

Understanding how Buffer Syringe and tools like it work should give IT managers much more confidence when evaluating, for example, a Windows vulnerability assessment tool or patch management system because it will reveal the ins and outs of how the buffer overflow is constructed.

With this information, IT managers can then exact much more specific and telling information from vendors of commercial vulnerability assessment tools as to how their tools detect such weaknesses. Thus armed, it will be much easier to evaluate, select, implement and use such tools over time.

Early in the methodical stalking of an IT resource, hackers will enumerate and identify systems in a network, looking for something of interest. After identifying an interesting target, smart hackers will gently test to see if any part of a system was left in a default configuration. Such a configuration provides easy back-door entry into what might look from the front like an impregnable fortress.

For Windows systems, start with sysinternals.com, where you'll find a host of useful no-cost and commercial diagnostic tools. -http://sysinternals.com/

Go to nessus.org to become familiar with one of the most widely used vulnerability assessment tools available. Nessus can probe a wide range of server and desktop operating systems and is frequently updated. - http://nessus.org/