Browser plug-ins and extensions are still not being updated often enough to close known security vulnerabilities, cloud security company Zscaler has reported.
The company's findings in its latest State of the Web report for Q2 have become a common refrain from a variety of sources that have studied the issue.
Plug-ins increasingly define how browsers are used and account for a growing proportion of Internet traffic despite remaining a huge security blind spot for consumer and business PCs users.
The company found that Adobe Flash is the commonest plug-in with nearly 94 percent penetration rates, followed by the other usual suspects, Windows Media Player, Adobe Reader, Outlook, and Adobe Shockwave.
Heading the updating problem list was Adobe Reader, which was found on 83 percent of PCs, 56 percent of which were out of date, with Shockwave present on 35 percent of PCs, nearly a third of which were out of date.
Two oddities among the statistics were Adobe's Flash and Java, both of which were out of date on a modest 8.4 percent and 6.5 percent of machines respectively despite Flash being the commonest plug-in. Java was recorded on only 9.2 percent on installations despite its near ubiquity in other surveys and huge popularity as an attack angle.
This is probably explained by the company's enterprise customer base which uses its cloud security services and from which it culls its numbers. There is evidence from separate studies that on consumer PCs that Java and Flash are two fo the most commonly targetted plug-ins with many users running out of date versions. On business systems this could be less significant thanks to patching discipline.
On the plug-in theme, the latest Firefox 6.0 features a checker that scans installed add-ons in order to give an overview of which ones require updates. The limitation of this appears to be that it doesn't scan all add-ons yet, only the most common ones.
Another trend spotted by Zscaler was the high level of Facebook traffic among the packets it filtered. This one application now accounts for 49 percent of the web traffic during the second quarter, dwarfing that for YouTube, Twitter, LinedIn, and even Gmail.
"Is this trend attributed to the fact more and more enterprises are now leveraging Web 2.0 and social networking, or is due to the fact that employees spending more time pursuing personal interests?," asked the researchers.