The iTunes Store component in Apple iOS before 9 does not properly delete AppleID credentials from the keychain upon a signout action, which might allow physically proximate attackers to obtain sensitive information via unspecified vectors.
https://support.apple.com/HT205212
http://www.securitytracker.com/id/1033609
http://www.securityfocus.com/bid/76764
http://lists.apple.com/archives/security-announce/2015/Sep/msg00001.html