Rise Of HTML5 Brings With It Security Risks

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.The fourth potential flaw relates to one of the HTML5's best features. The WebSocket API enables two-way communication over one transmission control protocol (TCP) socket. The Websocket.org web site uses the example of a stock ticker Web application to explain how WebSocket works. In a traditional HTTP designed browser, in order to display the most current price for a stock, the browser constantly pings the Web server for new information, a process called "polling." Because that wastes time and compute resources, WebSocket allows the web server to push the information out to the browser only when it has new information to share.

The feature, called asynchronous full duplex communication, drastically reduces the amount of unnecessary traffic between server and browser, says Bulman. In the example of the stock ticker app accessed by 10,000 end users in the experiment, the data traffic reduction ratio was 500 to 1.

The downside is that WebSocket disables a number of important network security tools. It takes over key network ports such as Port 80 that screen packets for any maladies and, in a WebSocket port, the packets lack the traditional headers that would be seen by a web application firewall to block suspicious packets. Reputation-based defenses also fail with WebSocket deployed.

Wedge Networks' solution to this dilemma is an approach it calls "deep content inspection," a feature, introduced in November 2011, of its WedgeOS operating system that powers its security appliances.

"We judge the content, the structure and the intent of the data in motion," says Hongwen Zhang, CEO of Wedge Networks.

Wedge offers a "unique architecture" to deliver high performance deep packet inspection, wrote Chenxi Wang, a Forrester analyst, in a report providing a market overview for the content security space for the third quarter of 2011.

"Using this deep content inspection engine, customers can conduct in-depth malware detection, DLP processing and content classification at line speed," Wang notes.

But Wedge competes with a number of well-known players in this space, including Cisco, Google, McAfee, Microsoft, Sophos and Symantec, among others, she said.

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