New Hotmail hole discovered

Javascript can be used to jimmy open Hotmail accounts, bugfinder says. Microsoft response: 'This is not a security issue.'

Just what the world didn't need: Another way to crack open Microsoft's beleaguered free, Web-based email system, Hotmail. But, that's exactly what noted Bulgarian bugfinder Georgi Guninski claims to have found.

Guninski, who has made a name for himself by finding security violations in browsers, has found that Hotmail enables Web-paged embedded Javascript code to run automatically.

This makes it possible for someone to write Web programs that could do anything from steal passwords to read others' mail. While it's long been known that active Web applets, whether written in ActiveX or Java, have the potential to pry open systems from the inside, this is the first case in which someone has shown that Hotmail is vulnerable to such attacks. Is this a purely theoretical hole or one that can only be used by crackers to attack users? The answer, unfortunately, is the latter: Correctly written JavaScript programs can, at the least, raid users' inboxes.

Microsoft is not claiming ownership of this latest problem. "This is not a Hotmail security issue. We see it as an example of people encouraging users to run malicious code on the Web," a Microsoft spokesperson said. "To protect yourself now, you can disable JavaScript, just disable it before using Hotmail, or do not open mail from unknown people when you think it might contain JavaScript," the spokesperson added. "Microsoft is investigating ways for Hotmail users to have greater security against threats posed by malicious use of JavaScript in email."

The latest Hotmail hole opens up because Hotmail doesn't handle the new HTML tag "STYLE." Java programmers and Webweavers use STYLE to insert JavaScript into HTML pages. The solution is to force Hotmail to handle STYLE in the same way it does ordinary JavaScript -- disabling it on arrival.

The fix may be simple, but the timing for Microsoft could not be worse. The latest Hotmail security breach follows by weeks a major Hotmail security meltdown. It took Microsoft hours to fix the problem, but millions of user accounts were left unprotected in the interim. Since that initial breach, the company has brought in TrustE and another auditing firm to help it head off future Hotmail security breaches.

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