The VNC (Virtual Network Computing) server running on this host does not require any authentication. An attacker can connect and remotely administer this machine. VNC is a graphical desktop sharing system which uses the RFB protocol to remotely control another computer. It transmits the keyboard and mouse events from one computer to another, relaying the graphical screen updates back in the other direction, over a network.
Possible system compromise.
Configure VNC server to require authentication.