WYCIWYG


What 'You Cache Is What You Get' is a Uniform Resource Identifier (URI) scheme commonly displayed in the address bar of Gecko-based Web browsers like Mozilla Firefox as when the Web browser is retrieving cached information. WYCIWYG is a play on the related acronym WYSIWYG.

Usage

Mozilla Firefox implements a registered, strictly internal URI scheme to sort and later reference locally cached pages that were generated or modified by a script on the client side.

Security issues

In 2007 Michał Zalewski reported that it was possible to bypass the same-origin checks and read from cached documents. It was possible at that time to access documents without proper same domain policy checks. This could have enabled an attacker to steal sensitive data, perform cache poisoning and execute their own code or display own content with URL bar and SSL certificate data of the original page. This was fixed in Firefox 2.0.0.5 and SeaMonkey 1.1.3.