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.

Multiple off-by-one errors in Nagios Core 3.5.1, 4.0.2, and earlier, and Icinga before 1.8.5, 1.9 before 1.9.4, and 1.10 before 1.10.2 allow remote authenticated users to obtain sensitive information from process memory or cause a denial of service (crash) via a long string in the last key value in the variable list to the process_cgivars function in (1) avail.c, (2) cmd.c, (3) config.c, (4) extinfo.c, (5) histogram.c, (6) notifications.c, (7) outages.c, (8) status.c, (9) statusmap.c, (10) summary.c, and (11) trends.c in cgi/, which triggers a heap-based buffer over-read.

Off-by-one error in the process_cgivars function in contrib/daemonchk.c in Nagios Core 3.5.1, 4.0.2, and earlier allows remote authenticated users to obtain sensitive information from process memory or cause a denial of service (crash) via a long string in the last key value in the variable list, which triggers a heap-based buffer over-read.