VNC - vncviewer password authentication question

I have two hosts on my home network, one is running Linux
and vncserver. When I type "vncserver :0" on the server,
it prompts me for a password, and created a passwd file
in ~/.vnc. Now on the client host, I can connect WITHOUT
entering a password by using the command:

vncviewer -passwd /home/myhome/.vnc/passwd rmthost.somedomain.com:0

What's to stop someone else from using the same vncviewer command
to access the server? It seems awfully insecure. I know I can
use iptables or configure my switch to deny access to port 5900,
but there must be a way to control this with VNC.

-Thanks

somebody <(E-Mail Removed)> wrote:
> I have two hosts on my home network, one is running Linux
> and vncserver. When I type "vncserver :0" on the server,
> it prompts me for a password, and created a passwd file
> in ~/.vnc. Now on the client host, I can connect WITHOUT
> entering a password by using the command:

> vncviewer -passwd /home/myhome/.vnc/passwd rmthost.somedomain.com:0

You've got the same password file on the client as on the server. Lots
of possible reasons for that - maybe you tried to run vncserver on both
at some point in the past, or you're using NFS/SMB to host your home
directory, or you use rsync, or ...

> What's to stop someone else from using the same vncviewer command
> to access the server?

They either need your password, or access to your password file, which
should be in a directory that only you can access (UNIX permissions).

Chris