The Google Chrome browser hack revealed this week could come down to a dispute over third-party software: A Google security expert says a zero-day flaw discovered by VUPEN Security researchers to bypass the browser's sandbox actually lies in Adobe Flash. But VUPEN isn't budging on its claims that its researchers successfully "owned" the browser software itself.
But for now, only VUPEN and its "three-letter" government agency customers know the details about the two zero-day vulnerabilities that VUPEN says it exploited and successfully used to bypass Chrome's sandbox and other security features.
"Nobody knows how we bypassed Google Chrome's sandbox except us and our customers, and any claim is a pure speculation," says Chaouki Bekrar, CEO and head of research at VUPEN. "We will not reveal the details on how we achieved the full compromise of Chrome and its sandbox. We can, however, say that we did use the default and built-in attack surface of the browser without using a Windows kernel vulnerability. All users of Chrome should be aware now that this browser can be fully hacked despite its famous sandbox and despite all the marketing that Google has been doing around its security."
Bekrar would neither confirm nor deny whether his firm found the bug in Chrome's Flash plug-in implementation, which comes with the browser. But he did say this when asked about it: "Google Chrome sandboxes all its default plug-ins; thus, exploiting a plug-in vulnerability is not enough to bypass the sandbox."
Google, meanwhile, is challenging VUPEN's claims of a bug in Chrome. Google security researcher Tavis Ormandy said in a Twitter post that "VUPEN misunderstood how sandboxing worked in chrome, and only had a flash bug."
A Google spokesperson said the Chrome team is still investigating VUPEN's claim that it hacked Chrome's famed sandbox feature. Chrome's sandbox, along with its use of Microsoft's DEP and ASLR technologies, thus far has made the browser relatively impenetrable to hackers.