This document discusses cross-site scripting (XSS) and introduces XSSShell, a tool that uses XSS vulnerabilities to execute commands on a victim's browser. It begins with an introduction to XSS and its risks, then outlines XSS types and demonstrates XSSShell by exploiting vulnerabilities in a demo application. The document aims to show how XSSShell works by establishing a server and injecting client-side JavaScript to create an administrative interface that can control infected browsers.