Android Fake ID Bug
There is a bug in Android that could allow a malicious application unrestricted access to the device and its data. Google has checked all apps in GooglePlay and they are all safe. If you only download apps from GooglePlay, you have nothing to worry about. If you have downloaded apps from an alternative source you may be at risk.
There is also a security setting in Android that restricts the downloading of applications from GooglePlay only, which is the default. Unless you have changed this setting to allow downloading of applications from other sources, you should be safe. You should never download applications from other sources.
For more detail see the BBC’s article at: http://www.bbc.com/news/technology-28544443