Information
The HostbasedAuthentication parameter specifies if authentication is allowed through trusted hosts via the user ofrhosts or /etc/hosts.equiv along with successful public key client host authentication. This option only applies to SSH Protocol Version 2.
Even though therhosts files are ineffective if support is disabled in /etc/pam.conf disabling the ability to userhosts files in SSH provides an additional layer of protection.
Solution
Edit the /etc/ssh/sshd_config file to set the parameter as follows:
HostbasedAuthentication no