By default, UUCP does not give permission for remote systems to run any commands; you must specify the commands that remote systems can run at the local system.

If you are willing to pass along files copied with uucp, or if you want to allow other direct systems to use wild cards when requesting files from your system, give the remote system permission to run the uucp command. If you do not assign execute permissions for the uucp program to another system, it can transfer files only to your system (meaning your system is a terminal node, or leaf-node) but not through your system (meaning your system is an intermediary node).

If a remote system has permission to run uucp, it can be an intermediary for another system to which it is connected. Your local system cannot distinguish if an incoming request from an authorized system originated at that system or at a system to which it is connected. Therefore, you must assume that the execute permission you give to a remote system can be inherited, or used, by another system to which it is connected.