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.
Icinga is a monitoring system which checks the availability of network resources, notifies users of outages, and generates performance data for reporting. In versions 2.5.0 through 2.13.0, ElasticsearchWriter, GelfWriter, InfluxdbWriter and Influxdb2Writer do not verify the server's certificate despite a certificate authority being specified. Icinga 2 instances which connect to any of the mentioned time series databases (TSDBs) using TLS over a spoofable infrastructure should immediately upgrade to version 2.13.1, 2.12.6, or 2.11.11 to patch the issue. Such instances should also change the credentials (if any) used by the TSDB writer feature to authenticate against the TSDB. There are no workarounds aside from upgrading.