Hackers can disable ‘Find My iPhone’ on iOS 7.0.4 and lower version without having to enter a password. The exploit was discovered and demonstrated by security researcher ‘Bradley Williams’ The vulnerability could put the devices at risk, and the exploitation method involves a few simple steps that involve making changes in the iCloud settings, even if they don’t know the password. It only works if the user hasn’t set a passcode or enabled the iPhone 5S fingerprint-based Touch ID system.
Source: https://thehackernews.com/2014/02/ios-vulnerability-allows-to-disable_8.html