HTML5 is the new "it" protocol on the Internet. Among other things, it is an alternative to Adobe's Flash for displaying content through a Web browser. No less an industry authority than the late Steve Jobs declared in 2010 that browsers on Apple devices such as the iPad would support HTML5 and not Flash. But as HTML5 gains wider adoption, some of its security flaws are beginning to get noticed, including the WebSocket specification that renders Web pages more quickly than does Flash.
"Anything new comes with some new security concerns," says Joe Bulman, systems architect for Wedge Networks, a network security company specializing in what it calls "deep content inspection" of traffic on Web networks.
HTML5 security issues have drawn the attention of the European Network and Information Security Agency (ENISA), which studied 13 HTML5 specifications, defined by the World Wide Web Consortium (W3C), and identified 51 security threats.
A recent alert from security vendor Sophos stated HTML5 provides far more access to the computer's resources than its predecessor, offering capabilities like location awareness, local data storage, graphics rendering and system information queries that are built in and quite powerful. However, the alert cautions that while the enhancements are great, "they radically change the attack model for the browser. We always hope new technologies can close old avenues of attack. Unfortunately, they can also present new opportunities for cybercriminals."
Bulman identified four main concerns. First is the problem of cross-origin resource sharing (CORS), in which a Web server can allow its resources to be accessed by a Web page from a different domain. While useful in aggregating content from several sites, he says, there is a risk that some content may be shared that shouldn't be. Second is the problem of click-jacking, in which malicious code is surreptitiously placed on a Web page image behind a digital mask that makes an item appear to be safe and invites the user to click on it. Third, HTML5 has unique geolocation and privacy issues that need to be addressed, although he adds that HTML5 standards bodies as well as browser vendors are addressing them.
In fact, to its credit, the HTML5 community is responsive and "transparent" in how it operates, he says. Also, HTML5 applications have more restricted access to system resources than with Flash, while HTML5 protocol updates are delivered through browser updates so they're more likely to be applied. All the major browser vendors are working on HTML5 security issues, and the HTML5 community enjoys the support of the Internet's biggest brands, including Facebook, Google, PayPal and Bing. This means that use of HTML5 should be on a strong growth curve.
