By the way, do not have sshd installed (and there is no /usr/sbin/sshd).I mentioned sshd as an example. There are plenty of ways to do remote connection to the host (telnet, VNC, XDMCP), all of them can be used for the root access. Just to be on a safe side, scan your host with 'nmap -sT -sU 1-65535' for both ipv4 and ipv6. Consider blocking everything unneeded with iptables.
Great! This thread starts to look like a small tutorial on useful commands!