...because you can't get enough of clickjacking
From: Michal Zalewski <lcamtuf () coredump cx>
Date: Fri, 12 Mar 2010 22:28:01 -0800
[ I promise to post something more interesting shortly - but in the meantime, I wanted to drop a quick note about something kinda amusing. ] There was a considerable amount of buzz around clickjacking [1] in the past year or so. It is commonly believed that this simple attack can only be realistically employed to exploit one-click UI actions. Alas, a related vector is generally overlooked: JS focus semantics - a source of considerable amount of grief in the past [2] - can be abused to execute multi-step attacks by altering focus between a hidden frame and the edited document while the user is simply typing something in. No need for pixel-accurate positioning of the target, too. Consider this whimsical proof-of-concept exploit (works on Windows, WebKit-based browsers only): http://lcamtuf.coredump.cx/focus-webkit/ It's not very serious, but more cuter than clickjacking proper. WebKit focus behavior on Windows makes this particular PoC easier there, but I believe that no browser is designed to counter this general attack pattern in any particular way. The usual opt-in mitigations (X-Frame-Options, frame busting) should offer a reasonable degree of protection already. [1] http://code.google.com/p/browsersec/wiki/Part2#Arbitrary_page_mashups_%28UI_redressing%29 [2] http://lcamtuf.coredump.cx/focusbug/ and so forth