The DocView server is initially configured to serve the documentation to any machine on your network. You can change the configuration to only serve to browsers running on the same machine.
If the search index has not been run since installation, then do the following step (a). If the search index has been run already, then do step (b). You can tell if it has been run because the file /usr/lib/docview/en/htdig.conf is not zero length (which means it has been configured).
Now when the index is run for the first time, it will be configured only for local access.
If the index has already been run at least once, then edit the file /usr/lib/docview/en/htdig.conf and change all instances of your fully qualified network hostname to 127.0.0.1. Be sure to leave the port number as 8457.