The latest version of Mozilla's Firefox web browser, version 5, was released on Tuesday with fixes for a number of vulnerabilities that could allow an attacker to crash a victim's browser, run arbitrary code on their computer, steal data or perform cross-site scripting attacks. Mozilla also fixed several security vulnerabilities in Firefox 3.6 this week, but ended support for Firefox 4, which was released just three months ago and received its only update, Firefox 4.0.1, in April. Users of Firefox 4 are being advised to upgrade to Firefox 5.