A few of my friends found multiple copies of ssh_config lying around, so I wrote this one-liner that looks at 3 separate known ssh_config files & patches any vulnerable ones that it finds.
$ for SSH_CONF in /etc/ssh/ssh_config /etc/ssh_config /private/etc/ssh_config; do [ -f $SSH_CONF ] && ! grep -q 'UseRoaming no' $SSH_CONF && echo "Patching $SSH_CONF" && echo -e '\nHost *\n UseRoaming no' | sudo tee -a $SSH_CONF > /dev/null; done
$ for SSH_CONF in /etc/ssh/ssh_config /etc/ssh_config /private/etc/ssh_config; do [ -f $SSH_CONF ] && ! grep -q 'UseRoaming no' $SSH_CONF && echo "Patching $SSH_CONF" && echo -e '\nHost *\n UseRoaming no' | sudo tee -a $SSH_CONF > /dev/null; done