status.cgi in Nagios 4.0 before 4.0 beta4 and 3.x before 3.5.1 does not properly restrict access to certain users that are a contact for a service, which allows remote authenticated users to obtain sensitive information about hostnames via the servicegroup (1) overview, (2) summary, or (3) grid style in status.cgi. NOTE: this behavior is by design in most 3.x versions, but the upstream vendor "decided to change it for Nagios 4" and 3.5.1.
http://tracker.nagios.org/view.php?id=456
http://seclists.org/oss-sec/2013/q2/622
http://seclists.org/oss-sec/2013/q2/619
http://lists.opensuse.org/opensuse-updates/2013-07/msg00031.html
http://lists.opensuse.org/opensuse-updates/2013-07/msg00029.html