Firefox to US$7,500 cash reward) to researchers who discover severe security holes in Firefox. Official guidelines for handling security vulnerabilities discourage early disclosure of vulnerabilities so as not to give potential attackers an advantage in creating exploits. Because Firefox generally has fewer publicly known security vulnerabilities than Internet Explorer (see "Comparison of web browsers"), improved security is often cited as a reason to switch from Internet Explorer to Firefox. "The Washington Post" reported that exploit code for known critical security vulnerabilities in Internet Explorer was available for 284 days in 2006. In comparison, exploit code for known, critical security vulnerabilities in
Pwn2Own not show up. No teams showed up for day three. Chrome and Firefox were not hacked. For 2012 the rules were changed to a capture-the-flag style competition with a point system. The new format caused Charlie Miller, successful at the event in past years, to decide not to attend. At Pwn2Own, Chrome was successfully exploited for the first time. VUPEN declined to reveal how they escaped the sandbox, saying they would sell the information. Internet Explorer 9 on Windows 7 was successfully exploited next. Firefox was the third browser to be hacked using a zero day exploit. Safari on Mac