Android Lollipop makes WebView flaws easier to patch

With Android 5.0 or Lollipop, Google has put in place a framework for improving the security of Android apps.

Among other security features in Android Lollipop, the OS will also be easier to fix the next time a security flaw is discovered in WebView, a key component of Android that allows app developers to expose web content within native apps.

The change is a big improvement on the current state for WebView. If a new security flaw is discovered in WebView on Android 4.0 (KitKat) and earlier versions, it would generally require an OEM to deliver the fix in a firmware update. And the well-known problem with Android firmware is that OEMs and carriers often don’t deliver updates to all devices or can be slow in doing so.

WebView has come under the scrutiny of security researchers a number of times in the past year. Earlier this year security firm Bluebox discovered a WebView flaw affecting all pre-KitKat Android that exposed them to malicious apps hijacking permissions from trusted apps on a device. Last month a WebView flaw exposed pre-KitKat devices to man-in-the-middle attacks. Fixing both flaws required a firmware update.

Android Lollipop is the culmination of two main changes in how WebView is handled compared to previous versions of Android. First, as noted by Android Police, Google settled on its own Chromium for WebView instead of WebKit when KitKat was released. But, as with earlier versions of Android, WebView was still part of the firmware. So, while KitKat was not affected by the two WebView flaws above, like earlier versions of Android, the only way to apply fixes was via a firmware update.

The second is that with Android Lollipop, the Chromium-based WebView can be updated by Google Play, which means updates to that component will be delivered to devices independent of carriers and OEMs.

“Although WebView has been based on Chromium since Android 4.4, the Chromium layer is now updatable from Google Play,” Google notes in on its developer site.

“As new versions of Chromium become available, users can update from Google Play to ensure they get the latest enhancements and bug fixes for WebView, providing the latest web APIs and bug fixes for apps using WebView on Android 5.0 and higher.”

WebView in Android 5.0 is still a bundled system app but, as Android Police points out, to stay current it will use the same mechanism employed in Google Play Services (GPS) — the services and APIs that Google uses to update its own key apps, such as Maps and Now, and ensure that feature updates arrive for nearly all Android devices and not just the latest version.

This article is brought to you by Enex TestLab, content directors for CSO Australia.