Researchers reveal 'clickjacking' attack info

Computerworld - The security researchers who two weeks ago warned of new "clickjacking" vulnerabilities in browsers, Web sites and popular plug-ins, revealed a dozen variants of the bug yesterday.

And that's just for starters, said Robert Hansen, founder and CEO of SecTheory LLC. "The list doesn't cover all the other kinds of plug-ins that are vulnerable, or all the browsers or all the Web sites," Hansen said in an interview Wednesday. "The list got so long so fast that it was impossible to keep track of all the sub-issues."

On Tuesday, Hansen disclosed more information about "clickjacking," the new class of vulnerabilities that he and fellow researcher Jeremiah Grossman, the chief technology officer at WhiteHat Security Inc., first mentioned during a semi-closed presentation at a New York security conference on Sept. 24. Hansen and Grossman had originally intended to present the bulk of their findings then, but agreed to withhold most of the information at the request of Adobe, which said it would quickly patch its software against clickjacking attack.

Early yesterday, however, Israeli researcher Guy Aharonovsky posted a proof-of-concept demonstration that uses clickjacking tactics to invisibly reset Adobe System Inc.'s Flash privacy settings, and secretly turn on the computer's webcam and microphone for remote spying.

With the cat out of the bag, Adobe gave Hansen and Grossman the go-ahead to get specific about their findings. Hansen then posted a list of 12 different clickjacking scenarios on his blog.

"There are multiple variants of clickjacking," Hansen said in the post. "Some require cross domain access, some don't. Some overlay entire pages over a page, some use iframes to get you to click on one spot. Some require JavaScript, some don't. Some variants use CSRF to pre-load data in forms, some don't."

Of the dozen he spelled out, only two have been resolved. Adobe has not, for example, patched Flash against one of the clickjacking vulnerabilities Hansen and Grossman reported to the company. Adobe issued a security advisory yesterday, however, with instructions on how to secure Flash against webcam and microphone hijacking in lieu of a patch.

"[Aharonovsky's] proof-of-concept was just a demonstration, but clickjacking can do all kinds of things," Hansen said today. "If you think about the traditional Web applications that have a 'Confirm' button or an 'Add a friend' button or any kind of single-button click, they're all going to be more vulnerable now."

But he also said there's no reason to panic; clickjacking wouldn't make the Internet a much more dangerous place in the short term. "If we assume that the majority of Web applications are vulnerable to some exploit, and they are, then clickjacking is making things worse, but it's already so bad that it doesn't really matter," Hansen said.