Information
As listener configuration changes via unencrypted remote connections can result in unauthorized users sniffing the control configuration information from the network, these control values should be set according to the needs of the organization.
Solution
Use a text editor such as vi to set the SECURE_REGISTER_<listener_name>=TCPS or SECURE_REGISTER_<listener_name>=IPC for each listener found in $ORACLE_HOME/network/admin/listener.ora.