Firefox users need to update their browser software following the release of updates designed to fix multiple security vulnerabilities.

Security bugs in the JavaScript engine used by the popular open source browser might be exploited to corrupt system memory, a type of attack that could allow hackers to inject hostile code onto vulnerable PCs.

There's also a flaw in the handling of XUL popups that means it might be possible to spoof the browser's location bar, a type of attack that phishing fraudsters would doubtless find useful.

There's little or no evidence that the flaws have been exploited to conduct hostile attacks, as yet. Nonetheless, users would be well advised to upgrade to version 2.0.0.4 or 1.5.0.12 of Firefox, just to be on the safe side. Thunderbird shares the browser engine with Firefox and could be vulnerable if JavaScript were to be enabled in mail, something that isn't a default setting and not recommended by the Mozilla Foundation.

Thunderbird users who nonetheless run JavaScript in mail received by the email client are advised to upgrade to version 2.0.0.4 or 1.5.0.12 of the software. SeaMonkey application suite users who enable JavaScript in emails need to upgrade to SeaMonkey version 1.0.9 and 1.1.2 for similar reasons.

As well as fixing various security bugs, Mozilla has introduced modifications with version 2.0.0.4 of its browser to enhance stability and improve support for Vista.

More background can be found via an advisory from the Mozilla Foundation here. ®

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