阻止iframe设置parent.location（防止帧爆破）

Question

I have a website on my own domain where i include iframes to other sites on other domains for quick preview purposes.

The problem is that some websites has framebusting code that redirects the user from my site.

How can i stop this. Even not showing the iframe at all would be better than the redirect in the case of a framebuster.

Shouldnt this redirect be blocked by the same site origin protection btw?

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Update

Ok, so it seems to be impossible to prevent it, but is it possible to just dont display the frame at all instead.

I tried with a double frame aproach: A and B is on my site, B contains C and when B gets window.onbeforeunload it sends a message to A to remove B. This didn't work either as the frames seem to have access all the way to the top window and not only the parent.

window.onbeforeunload works for blocking the redirect btw but then you have to display a dialog.

Answer 1

This can't be done because you can't access the DOM of the page in the iframe if it violates the same-origin policy.

Just don't do it. If people have framebusting code, they clearly don't want their page to be in a frame. Respect that.

Answer 2

How about running a test in a popup? Give it 20 seconds, if you still have control of the popup (ie the frame didn't change the document.url ) then load it in a new frame (?) and display to the user. Otherwise, don't show a frame at all. It's not foolproof but could work.

Answer 3

How can i stop this.

You can't. If you could, it would defeat the purpose of having frame-busting code in the first place.

Shouldnt this redirect be blocked by the same site origin protection btw?

That only protects you from accessing/modifying the DOM (ie document object) of a page. Frame-busting code only uses the window object to both detect frames and redirect to another page.

Answer 4

It's a cat-and-mouse game, but framebusting can be defeated.

According to researchers (PDF) from Stanford University and Carnegie Mellon University, frame-busting isn't as effective at preventing clickjacking as hoped. An analysis of the Top 500 Websites ranked by Alexa found all of the frame busting implementations could be circumvented. Some of the circumventions were browser-specific, while others worked across all browsers, the researchers found.

The original article on eweek ;
The research paper from Stanford (PDF)

Answer 5

If all you want is a preview of the website there are a number of services out there that do that. I have not used any, but a quick Google search finds this one

http://www.thumbshots.com/