The Network File System (NFS) service allows remote hosts to mount
and interact with shared filesystems on the local system. If the local system
is not designated as a NFS server then this service should be disabled.
The nfs-server service can be disabled with the following command:
$ sudo systemctl mask --now nfs-server.service
Rationale
Unnecessary services should be disabled to decrease the attack surface of the system.
ISA-62443-2-1-2009, Security for Industrial Automation and Control Systems Part 2-1: Establishing an Industrial Automation and Control Systems Security Program