CVE 2018-19977

A command injection (missing input validation, escaping) in the ftp upgrade configuration interface on the Auerswald COMfort 1200 IP phone 3.4.4.1-10589 allows an authenticated remote attacker (simple user) -- in the same network as the device -- to trigger OS commands (like starting telnetd or opening a reverse shell) via a POST request to the web server.

See the CVE page on Mitre.org for more details.