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24Sep/0815

New 0Day Browser Exploit: Clickjacking – OWASP AppSec NYC 2008

This talk was rumored to have been cancelled at a vulnerable vendors (Adobe) request, but Jeremiah Grossman and Robert Hansen decided to do parts of the talk anyway.  Here's my notes from the semi-restricted presentation.

Jeremiah started off with a brief introduction on what clickjacking is.  In a nutshell, it's when you visit a malicious website and the attacker is able to take control of the links that your browser visits.  The problem affects all of the different browsers except something like lynx.  The issue has nothing to do with JavaScript so turning JavaScript off in your browser will not help you.  It's a fundamental flaw with the way your browser works and cannot be fixed with a simple patch.  With this exploit, once you're on the malicious web page, the bad guy can make you click on any link, any button, or anything on the page without you even seeing it happening.  "A normal user wouldn't have any idea of what is going on.  People in this audience may see something a little different from what they would expect and you would definitely see the results in the page's source code."  Ebay, for example, would be vulnerable to this since you could embed javascript into the web page, although, javascript is not required to exploit this.  "It makes it easier in many ways, but you do not need it."  Use lynx to protect yourself and don't do dynamic anything.  You can "sort of" fill out forms and things like that.  The exploit requires DHTML.  Not letting yourself be framed (framebusting code) will prevent cross-domain clickjacking, but an attacker can still force you to click any links on their page.  Each click by the user equals a clickjacking click so something like a flash game is perfect bait. The issue and fix will probably be originally released on http://ihackcharities.org.

My Analysis: It sounds like the exploit basically creates a frame that is hidden underneath the main content frame that a user is seeing.  The main content could be a flash game or any sort of incentive to keep a user clicking.  All of the clicks that the user is making are used to click on content in the hidden frame. Again, just my speculation based on the information provided by RSnake and Jeremiah above.

24Aug/083

Two Simple Ways to Read Restricted Website Content

Have you ever had a problem that you used a search engine to try to find the solution?  Did that search bring you results from a site that then forced you to register in order to see the content?  This happened to me all of the time before I found two simple ways to display that content without me having to register at all.

Let me begin by explaining the why before I tell you the how.  In order for a search engine to index a site's content, it needs to be able to see that content.  The webmasters of that site are eager to let the search engine see the content as they know it will drive additional visitors to their site.  The end result is that they have to find a way for the search engine to see the content, while at the same time obscuring it from the view of the average user.  Most of the time they do this by keying off of the browser's USER AGENT.  This creates a loophole for us to exploit since if Google is able to see the search engine results, then so can we.  Here's my two tricks to see the restricted content: