iOS 9.0.2 has patched a potentially disturbing vulnerability which allowed malicious users who have access to your device to use Siri from the Lock screen in order to browse your photos and contacts.
According to Apple' official iOS 9.0.2 release notes, the software has fixed the issue which allowed access to photos and contacts on a locked device by “restricting options offered on a locked device.”
The vulnerability was left unpatched in iOS 9.0 and iOS 9.0.1 and affected the iPhone 4s and later, fifth-generation iPod touch and later and iPad 2 and later.