A Local File Inclusion (LFI) issue in the addon CUx-Daemon 1.11a of the eQ-3 Homematic CCU-Firmware 2.35.16 until 2.45.6 allows remote authenticated attackers to read sensitive files via a simple HTTP Request.
https://www.eq-3.com/products/homematic.html
https://noskill1337.github.io/homematic-with-cux-daemon-local-file-inclusion