Clickjacking allows someone to place an invisible link/button below your mouse as you browse a regular page. You think you’re clicking on a regular link, but really you are clicking someplace the attacker controls that’s hidden from you. Why is this important? Because it allows the attacker to force you to interact with something without your knowledge on a page other than the one you’ve been looking at. For example, they can hide a Flash application that follows your mouse around, and when you go to click a link it starts recording audio off your microphone. We have protections in browsers to prevent someone from automatically initiating certain actions. Also, many websites rely on you manually pressing buttons for actions like transferring large sums of money out of your bank account.

There are two sides to look at this exploitation- user and website owner. As a user, if you visit a malicious site (either a bad guy site, or a regular site that’s been hit with cross site scripting), the attacker can force you to take a very large range of actions. Anytime you click something, the attacker can redirect that click to the destination of their choice in the context of you as a user. That’s the important part here- it’s like cross site request forgery (really, an enhancement of it) that not only gets you to click, but to execute actions as yourself. That’s why they can get you to approve Flash applications you might not normally allow, or to perform actions on other sites in the background. As with CSRF, if you are logged in someplace the attacker can now do whatever the heck they want as long as they know the XY coordinates of what they want you to click.

As a website owner, clickjacking destroys yet more browser trust. When designing web applications (which used to be my job) we often rely on site elements that require manual mouse clicks to submit forms and such. As Robert (Rsnake) explains in his post, with clickjacking an attacker can circumvent nonces (a random code added to every form so the website knows you clicked submit from that page, and didn’t just try to submit the form without visiting the page, a common attack technique).

Clickjacking can be used to do a lot of different things- launching Flash or CSRF are only the tip of the iceberg.

It relies heavily on iFrames, which are so pervasive we can’t just rip them out. Sure, I turn them off in my browser, but the economics prevent us from doing that on a wide scale (especially since all the advertisers- e.g. Google/Yahoo/MS, will likely fight it).

Clickjacking is very difficult to eliminate, although we can reduce its risk under certain circumstances. Because it doesn’t even rely on Javascript and works with CSS/DHTML, it will take a lot of time, effort, and thought to eliminate.

If that sounded scary, have a look at a video showing one application of the exploit:

If you want to study that further, you can actually run it through it’s paces here.

So, what can be done about this? First of all, it’s worth realising that while it’s a powerful threat, the risk of it happening isn’t that high at the moment. Vendors have started recognising the threat and coming up with solutions for dealing with it. Adobe has come up with a workaround and NoScript has released ClearClick to help address it. It’s only a matter of time before this is quashed too (won’t be easy though)

Seems like there’s a new type of browser exploit that can cause problems to users out there. It’s called Clickjacking and here’s how it’s described:

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.

There’s a little more information about this on the Web Admin blog but details are still a bit sketchy. The biggest problem is that it seems to effect everyone using a browser, regardless if they’re using Firefox, IE or Chrome and whether they’re connected by dial-up, ADSL or satellite internet provider.

Hope this doesn’t cause too much consternation, because it seems like it’s not going to be trivial to fix this security hole.

• Apple has released a brand new version of their Safari browser, and it only took 2 hours for someone to hack an exploit out for it. There are some good reviews around as to what makes the software so compelling, but you might want to wait for the next version before you give it a try.
• Apple is opening up the iPhone API for 3rd party developers to write applications for it. This is an excellent move by Apple as it will help adoption of the new platform and quickly help iPhone sales reach critical mass. Closed platforms are very much a thing of the past, and many companies can leverage these APIs in different ways. It’s one thing that makes FaceBook so great.
• Seems like there are few iPhones being given to reviewers to write up and start to spread the buzz. Will be interesting to watch if the technology is all it’s cracked out to be, and if the iPhone really takes things to a brand new level.

Need to check when the European version of the iPhone will be out …