Firefox Updated With Critical Security Fix

Mozilla Corp. on Tuesday released a patch for a zero-day critical security hole in Firefox that could be exploited to crash the browser or install malicious code.

Firefox 1.5.0.3 fixes a zero-day vulnerability, which first appeared April 18 on Mozilla's Bugzilla listing. The flaw was found in Firefox 1.5.0.2, an update of the open-source browser that was released in mid-April.

Someone using malformed JavaScript code could use the bug to crash the browser, security officials said. JavaScript-based flaws are not uncommon with Firefox or its rival Internet Explorer from Microsoft Corp. Some of the 24 bugs fixed in the release of Firefox 1.5.0.2 were related to JavaScript.