Cross-Site Scripting (XSS) Explained Simply
Cross-site scripting (XSS) is a vulnerability that lets an attacker run their own JavaScript inside someone else’s browser session on your site. It is consistently one of the most common web bugs and also one of the most misunderstood. This guide makes it click: the three types, how a script ends up on your page, and how output encoding and a content security policy shut it down. It is written for developers, not specialists. In this guide What XSS is The three types: stored, reflected, DOM A concrete example Why it's dangerous The fix: output encoding Content Security Policy Framework protections and their gaps FAQ Quick answer: Cross-site scripting is when untrusted input is rendered into a page as HTML or script, so the browser runs it as code. The fix is context-aware output encoding—treat all user data as text when it reaches the page—backed by a content security policy as a second layer. What XSS is Cross-site scripting is an injection bug, closely...