CVE-2012-3733
Messages in Apple iOS before 6, when multiple iMessage e-mail addresses are configured, does not ensure that a reply’s sender address matches the recipient address of the original message, which allows remote attackers to obtain potentially sensitive information about alternate e-mail addresses in opportunistic circumstances by reading a reply.
Date published : 2012-09-20
http://lists.apple.com/archives/security-announce/2012/Sep/msg00003.html