The Promise and the Peril of HTML5

Like many software engineers, I love new toys. New programming languages allow us to create new features quickly, while handling tedious overhead issues, making it so we don’t have to think about them. However, in this desire to use the “new,” developers often forget to ask themselves, “How do we secure it?” Each feature of a new development tool may have security issues that we need to be aware of. However, in the rush to create, we don’t always educate ourselves thoroughly about the risks of those features. For example, HTML5 is becoming more popular now that all current browser versions support it, but developers need to be aware of the security issues they may encounter when utilizing certain HTML5 features.  

Offline Storage

What developer doesn’t want to take advantage of more storage space in the browser?! This enables us to store persistent user data. However, just like Spiderman’s Uncle Ben said, “With great power comes great responsibility.” Developers need to make sure that the data they are storing in the browser isn’t sensitive. Storing data that is considered sensitive by HIPAA, GLBA, or SOX regulations could result in severe legal ramifications and storing sensitive PCI data could lead to hefty fines. Developers must be made aware of what data is okay to store and which data should never be stored in the browser.

Geolocation

HTML5 gives us the ability to determine a user’s location and use that information to tailor search results, push notifications to the user about deals near them, and lots of other cool features.  However, developers need to be very careful about using geolocation because many end-users may not want their location to be used. They may consider their location to be sensitive information that they don’t want to be distributed. The geolocation functionality could easily be abused by malicious websites tracking users for nefarious purposes. 

Cross-Site Scripting

While many web developers are aware of cross-site scripting, they may be unaware that using HTML5 creates a new, unfamiliar attack surface. Each new feature within HTML5 such as local storage, canvas, and video capabilities could be implemented insecurely, giving an attacker the ability to run malicious scripts within the browser. Developers still need to carefully sanitize any input from one user that will be sent as output to other users in order to lower the risk of that output becoming malicious.

The thrill of using new tools and new programming languages will always attract developers. But we must get educated about securing any new functionality from these tools and languages before applications go into production.