rhn-migrate-classic-to-rhsm tool in Red Hat subscription-manager does not verify the Red Hat Network Classic server's X.509 certificate when migrating to a Certificate-based Red Hat Network, which allows remote man-in-the-middle attackers to obtain sensitive information such as user credentials.
https://exchange.xforce.ibmcloud.com/vulnerabilities/84020
https://bugzilla.redhat.com/show_bug.cgi?id=885130
http://www.securitytracker.com/id/1028520
http://www.securityfocus.com/bid/59674
http://secunia.com/advisories/53330