Information
The admin_restrictions_<listener_name> setting in the listener.ora file can require that any attempted real-time alteration of the parameters in the listener via the set command file be refused unless the listener.ora file is manually altered, then restarted by a privileged user.
Rationale:
Blocking unprivileged users from making alterations of the listener.ora file, where remote data/service settings are specified, will help protect data confidentiality.
Solution
To remediate this recommendation:
Use a text editor such as vi to set the admin_restrictions_<listener_name> to the value ON.
Default Value:
Not set.
References:
http://docs.oracle.com/database/121/NETRF/listener.htm#NETRF310