The following article is part two of my introduction to ZAP and testing WebSockets, in this episode I'll cover fuzzing. If you've not used ZAP before I suggest you look at some of the official tutorials first - ZAP home page, Videos. You can find my first part here OWASP ZAP and Web Sockets. The testing is being done against a small WebSockets based app I wrote called SocketToMe which has a few published services along with a few unpublished ones. In this article we are going to look at one of the published ones and try to identify some of the unpublished ones. The first feature I'll investigate is the number guessing game. Here the system picks a random number between 1 and 100 and you have to guess it. I'm going to cheat and see if I can get ZAP to play all 100 numbers for me to go for a quick win.