In the right circumstances, it is possible that input data can escape its designated buffer and flow into adjacent registers or segments of memory. This process will disrupt the execution flow and result in application or system crashes. In certain circumstances, buffer overflow vulnerabilities can also be leveraged to execute unauthorized code. In this particular recipe, we will demonstrate an example of how to perform a DoS attack based on buffer overflow against a Cesar 0.99 FTP service.
To perform remote fuzz testing, you will need to have a system that is running network services over TCP or UDP. In the example provided, a Windows XP system with an FTP service is used for this task. For more information on setting up a Windows system, please refer to the Installing Windows Server recipe in Chapter 1, Getting Started. Additionally, this section will require a script to be written to the filesystem, using a text editor such as VIM or...