Mozilla has released version 3.5.1 of Firefox which reportedly fixes the critical vulnerability. The vulnerability was disclosed publicly and could be exploited by hackers to run malicious code on your computer. Users are strongly encouraged to use the NoScript addon to increase their level of security. The NoScript add-in-time (JIT) addon has been added to Firefox to increase the security of the browser. Read more from Graham Cluley on the Naked Security website here: http://www.nakedsecurity.com/news/nakedSecurity-Security-Watchdog.”]
Source: https://grahamcluley.com/firefox-351-released-fix-major-security-problem/