Clickjacking (also known as UI redressing and iframe overlay) is a malicious technique where a user is tricked into clicking on a button or link on a website using hidden clickable elements inside an invisible iframe. This attack hijacks clicks intended for the visible page and routes the user to an application and/or domain on another page. The Barracuda Web Application Firewall as a Service uses the X-Frame-Options HTTP response header to detect and prevent iframe-based clickjacking. The X-Frame-Options header is inserted to indicate whether a browser should be allowed to render a page in a iframe, and if allowed, the iframe origin that needs to be matched.