Re: Xlib: connection to ":0.0" refused by server?

On Mon, Aug 26, 2002 at 01:20:24PM +0100, Toby Dickenson wrote:
> On Sunday 25 August 2002 23:24, [email protected] wrote:
> > On Sun, Aug 25, 2002 at 06:11:25PM -0400, Bob Paddock wrote:
> > > If I'm logged in as 'bob' and I su root, then try to start some thing
> > > like emacs I get this:
> > >
> > >
> > > root@bob cups # emacs error_log&
> > > [1] 6860
> > > root@bob cups # Xlib: connection to ":0.0" refused by server
> > > Xlib: No protocol specified
> > >
> > > emacs: Cannot connect to X server :0.0.
> > > Check the DISPLAY environment variable or use `-d'.
> > > Also use the `xhost' program to verify that it is set to permit
> > > connections from your machine. [This is the same machine!?]
> 
> I you use 'su -' it will clear all environment variables such as DISPLAY, and 
> you will be able to use a text mode emacs.
> 
> > before you su, type 'xhost +localhost'
> 
> Eeeek. It depends on the configuration of your machine (of course), but using 
> xhost like that is likely to be a security problem. It means that any process 
> on your machine can connect to your X server to snoop on your windows, record 
> keystrokes, etc.

afaik, there's only a security problem when you type xhost +
it says: access control disabled, clients can connect from any host
but, when you type xhost +localhost only the localhost is allowed to
make connections. don't think that is a security hole. (if i'm not
mistaken)


> 
> You may want to look at ssh, which can perform secure X forwarding.
> 'ssh -l root localhost' will let you run X emacs as root, without the security 
> hole.

in that case, make sure that X11 forwarding is enabled in your
sshd_config. default is disabled in gentoo

greetz,
stijn

> _______________________________________________
> gentoo-newbies mailing list
> [email protected]
> http://lists.gentoo.org/mailman/listinfo/gentoo-newbies