Foreman before 1.8.1 does not set the secure flag for the _session_id cookie in an https session, which makes it easier for remote attackers to capture this cookie by intercepting its transmission within an http session.
https://groups.google.com/forum/#%21topic/foreman-announce/QPtN0h04jdo
https://github.com/theforeman/foreman/pull/2328
https://bugzilla.redhat.com/show_bug.cgi?id=1216035
https://access.redhat.com/errata/RHSA-2015:1592