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.