That finding comes from research conducted by vulnerability management and security policy compliance vendor Qualys. The results are based on the 200,000 people who, over the past 6 months, used the company's free BrowserCheck tool, which looks for known vulnerabilities in Internet Explorer, Firefox, Chrome, Safari, and Opera browsers, running on Windows, Mac OS X, or Linux machines.
Interestingly, but not surprisingly, more than half of browser vulnerabilities stem from plug-ins. "The number was very high for the plug-ins, higher than I had expected," said Wolfgang Kandek, CTO of Qualys, in an email interview.
The most common insecure browser plug-ins in use are (in order): Java, Adobe Reader, QuickTime, Flash, Shockwave, and Windows Media Player. Many of these plug-ins are widespread -- 97% of computers have the Adobe Flash plug-in installed, and 95% have one for Windows Media Player.
Meanwhile, only about 20% of browsers are insecure due to the native browser application (not counting plug-ins). Kandek said that's testament to browser makers' structured approach to updates, which includes alerting users or simply updating browsers automatically when a new version becomes available.
Unfortunately, few plug-ins auto-update. Accordingly, it's up to IT departments to secure them. "Focus attention on the plug-ins of the browsers, determine if plug-ins are actually necessary, [and] look for plug-ins that have an update program," said Kandek.
Some good news from this study, while 80% of consumers today are using insecure browsers, that's down from a high of nearly 90% in June 2010. What accounts for the improvement? "A number of factors play a role for the small decline, but we have seen good acceptance of the new Adobe Reader X, which has reduced the exposure for PDF users in general," said Kandek.
Adapted from Mathew J. Schwartz article, InformationWeek Feb. 23, 2011