D-Bus provides an IPC mechanism used by a growing list of programs, such as
those used for Gnome, Bluetooth, and Avahi. Due to these dependencies,
disabling D-Bus may not be practical for many systems.
The messagebus service can be disabled with the following command:
$ sudo systemctl mask --now messagebus.service
If no services which require D-Bus are needed, then it can be disabled. As a broker for IPC between processes of different privilege levels, it could be a target for attack. However, disabling D-Bus is likely to be impractical for any system which needs to provide a graphical login session.