A Remote Code Execution (RCE) vulnerability in the WebUI component of the eQ-3 HomeMatic CCU2 firmware up to and including version 2.57.5 and CCU3 firmware up to and including version 3.57.5 allows remote unauthenticated attackers to execute system commands as root via a simple HTTP request.
https://www.eq-3.de/downloads/software/firmware/ccu3-firmware/CCU3-Changelog.3.59.6.pdf
https://novag.github.io/posts/homematic-unauthenticated-remote-code-execution/