One of the good things about writing a weekly blog is the impetus it provides to keep studying different topics. This week Cross-site Scripting (XSS) is in the crosshairs, as it is of the most common security vulnerabilities in software (see chart below, sourced from the WHID. Essentially an attacker embeds a script on a page, which is then executed on the client-side rather than on the server-side. Typical client-side scripting languages are HTML and JavaScript, or even SVG.