Writing exploit modules

Developing an exploit is one of the most interesting aspects of the Metasploit framework. In this section, we will briefly discuss the core issues surrounding the development of an exploit, and explain its key skeleton by taking a live example from the existing framework's database. However, it is important to be adept with the Ruby programming language before you attempt to write your own exploit module. On the other hand, intermediate skills of reverse engineering and practical understanding of vulnerability discovery tools (for example, fuzzers and debuggers) provide an open map towards the exploit construction. This section is meant only as an introduction to the topic, and not a complete guide.

For our example, we have selected the exploit (EasyFTP Server <= 1.7.0.11 MKD Command Stack Buffer Overflow), which will provide a basic view of exploiting buffer overflow vulnerability in the Easy FTP Server application. You can port this module for a similar vulnerability...