ALERT!!!!! HOW TO: Spy on the Webcams of Your Website Visitors

ALERT!! – I would read this because cops could be watching you.     I discovered a vulnerability in Adobe Flash that allows any website to turn on your webcam and microphone without your knowledge or consent to spy on you.

It works in all versions of Adobe Flash that I tested. I’ve confirmed that it works in the Firefox and Safari for Mac browsers. Use one of those if you check out the live demo. There’s a weird CSS opacity bug in most other browsers (Chrome for Mac and most browsers on Windows/Linux).

Updates about the vulnerabilty

Clickjacking + Adobe Flash = Sad Times!

This attack works by using a neat variation of the normal clickjacking technique that spammers and other bad people are using in the wild right now. For the uninitiated:

Clickjacking is a malicious technique of tricking Web users into revealing confidential information or taking control of their computer while clicking on seemingly innocuous web pages.

— Wikipedia

Combine clickjacking with the Adobe Flash Player Setting Manager page and you have a recipe for some sad times.

Background

I took a computer security class (Stanford’s CS 155) last quarter and really enjoyed this research paper on framebusting and clickjacking. After reading it, I checked out a few popular sites to see if it was possible to clickjack them. After a couple hours, I had no success.

But, then I stumbled upon this blog post entitled “Malicious camera spying using ClickJacking” where the author shows how to clickjack the Adobe Flash Settings Manager page to enable users’ webcams. He accomplishes this by putting the whole settings page into an iframe and making it invisible. Then, unsuspecting users play a little game and unwittingly enable their webcams. Adobe quickly added framebusting code to the Settings Manager page (why wasn’t it there in the first place?), and the attack stopped working.

But alas, the same attack is actually still possible.

How my attack works

Instead of iframing the whole settings page (which contains the framebusting code), I just iframe the settings SWF file. This let me bypass the framebusting JavaScript code, since we don’t load the whole page — just the remote .SWF file. I was really surprised to find out that this actually works!

I’ve seen a bunch of clickjacking attacks in the wild, but I’ve never seen any attacks where the attacker iframes a SWF file from a remote domain to clickjack it — let alone a .SWF file as important as one that controls access to your webcam and mic!

The problem here is the Flash Player Setting Manager, this inheritance from Macromedia might be the Flash Player security Achilles heel.

— Guy Aharonovsky

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