Printing UIKit in Apple iOS before 10 mishandles environment variables, which allows local users to discover cleartext AirPrint preview content by reading a temporary file.
https://support.apple.com/HT207143
http://www.securitytracker.com/id/1036797
http://www.securityfocus.com/bid/92932
http://lists.apple.com/archives/security-announce/2016/Sep/msg00008.html
http://lists.apple.com/archives/security-announce/2016/Sep/msg00002.html