An analysis of how quickly different browser users patch Adobe Flash vulnerabilities shows a marked variation among browser makers. The data suggest that Google Chrome and Mozilla Firefox users tend to get Flash updates relatively quickly, while many users on Microsoft’s Internet Explorer browser consistently lag behind.
The information comes from ThreatMetrix, a company that helps retailers and financial institutions detect and block patterns of online fraud. ThreatMetrix Chief Technology Officer Andreas Baumhof looked back over the past five months across 10,000+ sites the company serves, to see how quickly visitors were updating to the latest versions of Flash.
Baumhof measured the rates of update adoption for these six Flash patches:
Overall, Google Chrome users were protected the fastest. According to Baumhof, Chrome usually takes just a few days to push the latest update out to 90 percent of users. Chrome pioneered auto-updates for Flash several years ago, with Firefox and newer versions of IE both following suit in recent years.
Interestingly, the data show that IE users tend to receive updates at a considerably slower clip (although there are a few times in which IE surpasses Firefox users in adoption of the latest Flash updates). This probably has to do with the way Flash is updated on IE, and the legacy versions of IE that are still out there. Flash seems to have more of a seamless auto-update process on IE 10 and 11 on Windows 8 and above, and more of a manual one on earlier versions of the browser and operating system.
Another explanation for IE’s performance here is that it is commonly used in business environments, which tend to take a few days at least to test patches before rolling them out in a coordinated fashion across the enterprise along with the rest of the Patch Tuesday updates.
The following graphic depicts Flash patch adoption by IE version for Period #4 in the image above (Mar 11, 2014 - APSB14-08 Security updates available for Adobe Flash Player (2 critical vulnerabilities)):
“In the period 4 you can see that IE11 is nicely up to 90% – which is in line with Chrome, but obviously the older the browser version, the less updated Flash is,” Baumhof said.
It’s unclear what might explain the apparent slow uptake of Flash patches for IE and Firefox users following the January and early April Flash updates. It’s worth noting, however, that the Flash patches which saw the fastest uptake regardless of browser type included fixes for zero-day vulnerabilities (see periods 2, 3 and 6 in the first graphic above).
While Chrome appears to have the speediest update process for Flash patches (the company frequently pushes Flash updates out even before Adobe releases them publicly), it’s important to remember that applying any auto-pushed Flash patches in Chrome requires a restart of the browser.
“I use Chrome and I typically never close my browser as I always just hibernate my computer,” Baumhof said. “I noticed that it took me almost seven days to apply a Flash update because Chrome could only do this when you restart the browser, and I simply wasn’t aware of it.”
Flash is a buggy security risk, but a great many Web sites simply won’t work or display certain content without the Flash plugin installed. As such, I’ve urged readers to take advantage of Click-to-Play, which blocks plugin activity by default, replacing the plugin content on the page with a blank box. Users who wish to view the blocked content need only click the boxes to enable the Flash content inside of them.