An issue was discovered in Icinga2 before v2.12.0-rc1. The prepare-dirs script (run as part of the icinga2 systemd service) executes chmod 2750 /run/icinga2/cmd. /run/icinga2 is under control of an unprivileged user by default. If /run/icinga2/cmd is a symlink, then it will by followed and arbitrary files can be changed to mode 2750 by the unprivileged icinga2 user.
Exploitability
AV:LAC:LPR:LUI:NScope
S:UImpact
C:HI:HA:H7.8/CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H