Information
The SECURE_REGISTER_<listener_name> setting specifies the protocols used to connect to the TNS listener. Each setting should have a value of either TCPS or IPC based on the needs for its protocol.
Rationale:
Listener configuration changes via unencrypted remote connections can result in unauthorized users sniffing control configuration information from the network.
Solution
To remediate this recommendation:
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.