Metasploit:-Beast Unleashed - Writing A simple Fuzzer.

Writing A Simple Fuzzer:-

Fuzzers are tools used by security professionals to provide invalid and unexpected data to the inputs of a program. Typical fuzzers test an application for buffer overflows, format string, directory traversal attacks, command execution vulnerabilities, SQL Injection, XSS and more. Because Metasploit provides a very complete set of libraries to security professionals for many network protocols and data manipulations, the framework is a good candidate for quick development of simple fuzzers.

Rex::Text module provides lots of handy methods for dealing with text like:

Buffer conversion
Encoding (html, url, etc)
Checksumming
Random string generation

The last point is obviously extremely helpful in writing simple fuzzers. For more information, refer to the API documentation at http://metasploit.com/documents/api/rex/classes/Rex/Text.html. Here are some of the functions that you can find in Rex::Text :