Icinga 2 is an open source monitoring system. From 2.10.0 to before 2.15.1, 2.14.7, and 2.13.13, the safe-reload script (also used during systemctl reload icinga2) and logrotate configuration shipped with Icinga 2 read the PID of the main Icinga 2 process from a PID file writable by the daemon user, but send the signal as the root user. This can allow the Icinga user to send signals to processes it would otherwise not permitted to. A fix is included in the following Icinga 2 versions: 2.15.1, 2.14.7, and 2.13.13.