ActiveX controls made up <A HREF="http://www.techworld.com/news/index.cfm?RSS&NewsID=11967">most of all browser plug-in vulnerabilities</A> in the second half of 2007, according to Symantec.

The company has just released its semi-annual Web security report and in it said that Microsoft's technology, primarily used to create add-ins for Internet Explorer, accounted for 79 percent of the 239 plug-in bugs discovered between July and December 2007. The plug-in with the next-highest number of flaws was Apple's QuickTime, which had just 8 percent of the six-month's total.

Only one vulnerability in a plug-in for Mozilla's Firefox browser was detected in the same period, meaning Firefox's extensions--the moniker Mozilla uses for plug-ins--accounted for only 0.4 percent of all found flaws.