An alternative to stopping a service completely is to block access to it from untrusted hosts. The easiest way to do this is to install a `Packet Filter', which is the simplest type of firewall. It simply rejects or drops packets based on the source or destination IP address and/or the source/destination protocol and port.
Packet Filters are simple, yet effective in many cases. It must be stressed, however, that they have problems. Machines, particually those on the local subnet, may be able to forge packets to bypass packet filtering rules. It must also be noted that a packet filter does not improve the security of a service, merely limit the people who can easily connect to it. You should also consider what happens in one of the hosts you are allowing access gets broken into.