In this book, we will use the tools provided by Kali Linux to accomplish our testing. Kali Linux is a Debian-based GNU/Linux distribution. Kali Linux is used by security professionals to perform offensive security tasks, and it is maintained by a company known as Offensive Security. The predecessor of Kali Linux is BackTrack, which was one of the primary tools used by penetration testers for more than six years until 2013, when it was replaced by Kali Linux. In August 2015, the second version of Kali Linux was released with the code name Kali Sana, and in January 2016, it switched to a rolling release.
This means that the software is continuously updated without the need to change the operating system version. Kali Linux comes with a large set of popular hacking tools, which are ready to use with all of the prerequisites installed. We will take a deep dive into the tools and use them to test web applications that are vulnerable to major flaws which are found in real-world web applications.