"However, it turns out that the fix was not complete as one can still abuse invokeWithArguments method to setup calls to invokeExact method with a trusted system class as a target method caller, " Gowdiak wrote.

CNN: STORY HIGHLIGHTS

After a simple setup, parents can activate a specialized place on the phone for kids to play - complete with their own customizable Start screens - where they can access only the apps, games, music and videos picked by parents.

ENGADGET: Microsoft brings guest user account to Windows Phone 8 via Kid's Corner