Jan Bee of the Google Security Team reports:
The /usr/sbin/rhnreg_ks fails to properly validate hostnames in certificates.
This can result in man in the middle attacks.
Please note that this issue cannot easily be exploited to cause any significant
damage to a system other then preventing registration from taking place properly
which the attacker would be able to do in any event if the can man in the
middle the connection.
This issue affects the versions of rhn-client-tools as shipped with Red Hat Enterprise Linux 5, 6 and 7. Red Hat Product Security has rated this issue as having Moderate security impact. A future update may address this issue. For additional information, refer to the Issue Severity Classification: https://access.redhat.com/security/updates/classification/.