New Browsers, New Bugs

Two have already been reported in the new Internet Explorer 7. Will Firefox 2.0 face the same fate?

Internet Explorer 7, Firefox 2.0: Secure browsing is finally here.

Or is it?

It's been a big month for these long-awaited, next-generation browsers, with Microsoft's IE7 arriving last week and Mozilla's Firefox 2.0 yesterday, both with built-in anti-phishing features. But as soon as IE7 left the gate in Redmond there was a report of its first bug, a URL handler problem, and today a URL spoofing bug that can be used by phishers.

Microsoft had not yet commented on the second vulnerability at presstime. But this latest flaw ironically opens the door for phishing, something IE7 was built to combat. As for the first bug, Christopher Budd, with Microsoft's Security Response Center, said in the MSRC blog that the redirect vulnerability actually lies in Outlook Express, not IE7. IE7 was merely an attack vector in the reports of the bug. "While these reports use Internet Explorer as a vector, the vulnerability itself is in Outlook Express," he said, adding that Microsoft was investigating.

So will Firefox 2.0, too, be hammered on by hackers in search of bugs?

Although IE has traditionally been a bigger target than Firefox, security researchers say no browser is really safe. "Both browsers definitely have their pros and cons," says RSnake, founder of "There has been nearly as many issues with [pre-2.0 release] Firefox as IE recently. I don't consider Firefox to be a wildly safer browser [than IE7]."

Because Firefox is open source, it's a bigger target for exploitation. But that also means it has a faster patching cycle, too, RSnake says, which is good news. Some researchers are even placing bets on how long it will take a Firefox 2.0 bug to be reported.

Meanwhile, researchers were surprised an old-school URL spoofing vulnerability was found in IE7. "URL spoofing vulnerabilities are common and were used in phishing attacks for years," says Jeremiah Grossman, CTO of White Hat Security. "It's surprising these issues are still cropping up in modern Web browsers."

Still, most browser vulnerabilities don't actually lie in the browser itself, but in the interactions between other systems and programs, RSnake says. "As more and more different groups develop for a platform you get further and further away from the original security models."

— Kelly Jackson Higgins, Senior Editor, Dark Reading

  • Microsoft Corp. (Nasdaq: MSFT)
  • Mozilla
  • WhiteHat Security