Secunia has reported that it found more security holes in Firefox than Internet Explorer, Apple Safari and other browsers in 2008, but Mozilla was quicker to plug its browser's security holes than Microsoft, when security flaws were disclosed publicly. Secunia is Denmark based computer security firm best known for tracking vulnerabilities in more than 12,400 pieces of software and operating systems.

According to Secunia, 115 security flaws were reported in Mozilla's Firefox in 2008-nearly twice as many as Microsoft's IE and Apple's Safari combined, but Mozilla was faster to react to fix the flaws than Microsoft, when the flaws were made public either prior to or without vendor notification.

Secunia reported that Mozilla reacted quickly when Firefox's three security holes were disclosed publically last year. Mozilla patched all three security holes, with the longest patch taking 86 days to arrive. On the contrary, Microsoft just fixed three of IE's six security flaws as of Dec. 31. Secunia reported that one of IE's security holes remained open for 294 days in 2008.

Secunia reported that all the security flaws were not rated equal. Firefox's three security flaws were rated "less critical," while three of IE's unpatched flaws were rated either "not critical" or "less critical," Two were classified as "moderate" and "high," while sixth flaw was rated "less critical".

Mozilla released an update to fix eight security flaws in Firefox 3.07, of which six were rated critical, on March 4. Mozilla released update, after Opera issued a security update for its browser, and roughly a week after Apple released a beta version of Safari 4.