Authorising binding to ports from 512 to 1023 inclusive is
not recommended. Some protocols (including some versions of NFS)
authorise clients by seeing that they are using a port number in this
range. So by authorising a program to be a server for such a port,
you are also authorising it to impersonate the whole host for those
protocols. To make sure that this isn't done by accident,
Authorising binding to ports from 512 to 1023 inclusive is
not recommended. Some protocols (including some versions of NFS)
authorise clients by seeing that they are using a port number in this
range. So by authorising a program to be a server for such a port,
you are also authorising it to impersonate the whole host for those
protocols. To make sure that this isn't done by accident,