Silly PoCs continue: X-Frame-Options give you less than expected

[Nytro]

Silly PoCs continue: X-Frame-Options give you less than expected

From: Michal Zalewski <lcamtuf () coredump cx>

Date: Fri, 16 Dec 2011 11:21:49 -0800

[ Resubmitting - I think the original post did not go through last

week, but some of the responses did, so probably an accident. ]

---

I think we greatly underappreciate the extent to which JavaScript

allows you to exploit the limits of human perception. On modern

high-performance systems, windows can be opened, positioned, and

closed; and documents loaded and then navigated away from; so quickly

that we can't even reliably notice that, let alone react consciously.

The PoC I posted here earlier this week

(Beaver Peak Banking and BBQ) demonstrates one example of page

transitions occurring so fast that you don't register it; and some of

my earlier posts outlined the exploitation of page switching to

exploit browser UIs (e.g. http://lcamtuf.coredump.cx/ffgeo2/). Today,

I wanted to share this brief demonstration of an attack that should

hopefully illustrate why our current way of thinking about

clickjacking (and the possible defenses, such as X-Frame-Options) is

flawed:

http://lcamtuf.coredump.cx/clickit/

The basic idea here is that instead of placing the UI you want to

tamper with in an invisible or only partly-visible <iframe>, you can

achieve a similar effect simply by predicting the time of a

premeditated click (which is fairly easy if you look at mouse velocity

and distance to the expected destination), and then either destroying

the current window, or navigating to a different document (in this

case, a cheesy banking site).

While everything about this exploit is extremely goofy, and I put no

effort into making the transitions less obvious, it should still

demonstrate the issue neatly.

/mz

Sursa: Bugtraq: silly PoCs continue: X-Frame-Options give you less than expected