Just a few short weeks after the iOS 9.3.3 update (see “Apple Releases OS X 10.11.6, iOS 9.3.3, tvOS 9.2.2, and watchOS 2.2.2,” 18 July 2016), Apple has released iOS 9.3.4. It contains a single security fix for an IOMobileFrameBuffer vulnerability that could allow apps to execute arbitrary code with kernel privileges. That means that a malicious app could do nearly anything it wanted on the device.
It’s unusual for Apple to update an operating system for just one vulnerability, which suggests that the potential exploit may be more concerning than many others. As such, we recommend that you install iOS 9.3.4 soon. It’s a roughly 25 MB download, and you can update via Settings > General > Software Update or through iTunes.