Mozilla patches 11 Firefox bugs

Computerworld - Mozilla Corp. late yesterday patched Firefox to quash 11 bugs, including one from three weeks ago that posed a threat to users who had installed any of the more than 600 add-ons for the open-source browser.

Firefox 2.0.0.12 fixed four vulnerabilities that Mozilla ranked "critical," one it pegged "high" and three each rated as "moderate" and "low," according to the security advisory posted Thursday. The new edition patched more flaws than any update since July 2007. Mozilla last patched Firefox in November.

Although it didn't receive Mozilla's highest threat ranking, the vulnerability in the browser's chrome: URI (Uniform Resource Identifier), disclosed by researcher Gerry Eisenhaur, got the most attention. That bug, which Eisenhaur said could be exploited through a huge number of Firefox's extensions, had been the subject of several blog postings by Window Snyder, Mozilla's chief of security.

She added another today. "This security update addresses the directory traversal issue," Snyder said.

The update also patched several critical vulnerabilities that had not been publicly revealed, including one that could allow attackers to steal users' browsing histories -- perhaps to gain information such as account passwords entered in earlier sessions. Other vulnerabilities included one that could be used for cross-site scripting attacks and one that crashed either the browser or the JavaScript engine, or both.

Unlike other vendors, Mozilla labels vulnerabilities as "critical" even when it's not certain that an exploit could result in an attacker introducing malicious code. The description for the browser and JavaScript engine flaw, for example, illustrated Mozilla's conservative approach: "Some of these crashes showed evidence of memory corruption under certain circumstances and we presume that with enough effort at least some of these could be exploited to run arbitrary code," the write-up read.

Also late yesterday, the company announced that final testing has started on Firefox 3.0 Beta 3, the most recent build of the major upgrade expected to ship in the next two months. If all goes according to plan, Mozilla said, Beta 3 will be released on Tuesday.

Previously, Mozilla had said it would need at least one more beta before moving Firefox 3.0 into the release candidate stage.

Firefox 2.0.0.12 can be downloaded from Mozilla in versions for Windows, Mac OS X and Linux. Forty localized editions, including a beta of the Kurdish Firefox, are available. Current Firefox users should be notified of its availability in the next day or two by the browser's automatic update tool.