This section describes selected network services that are usually provided as part of the standard Unix network package, focusing on the major security implications of each of these services.
Every network service carries both known and unknown security risks. Some services have relatively small known risks, while others have substantial ones. And with every network service there is the possibility that a security flaw in the protocol or the server will be discovered at some point in the future. Thus, a conservative security policy would remove every service for which there is no demonstrated need.