"Web pages know what Web sites you've been to ..., where you're logged in, what you watch on YouTube, and now they can literally 'see' and 'hear' you," warned Jeremiah Grossman, founder and CTO of WhiteHat Security, in a blog post.
Grossman and Robert "RSnake" Hansen, founder and CEO of SecTheory, discovered the clickjacking technique, called "UI redressing" by some, and planned to discuss it at the 2008 Open Web Application Security Project USA NYC security conference last month. But the pair decided to delay disclosure to allow affected vendors time to address the issue.
Unfortunately, this hasn't proven to be easy because clickjacking encompasses a range of attack techniques and affects a variety of software applications, including the major Web browsers and a number of plug-ins like Adobe Flash.
Clickjacking, as Grossman previously described the attack, "gives an attacker the ability to trick a user into clicking on something only barely or momentarily noticeable. Therefore, if a user clicks on a Web page, they may actually be clicking on content from another page."
Adobe on Tuesday issued a security advisory that describes a way to mitigate the risk faced by those with Adobe Flash Player installed -- almost everyone online. The advisory applies to Adobe Flash Player 220.127.116.11 and earlier.
Adobe recommends setting the "Always deny" button in the Global Privacy Settings panel of the Adobe Flash Player settings. The company is also working on an update to its Flash Player software that will address the vulnerability.
How to defend against clickjacking? "Put tape over your camera, disable your microphone, install NoScript, and/or disable your plug-ins," advises Grossman, even as he concedes few users will be willing to lose access to YouTube and Flash games as a result.
Nevertheless, U.S. CERT said much the same thing in an advisory late last month.