oss-sec mailing list archives

Re: virtual consoles


From: Leonid Isaev <leonid.isaev () ifax com>
Date: Mon, 2 Dec 2019 17:50:43 +0000

On Mon, Dec 02, 2019 at 06:28:12PM +0100, Solar Designer wrote:
On Mon, Dec 02, 2019 at 08:56:38AM -0800, Tavis Ormandy wrote:
Regardless of your position, this is certainly possible on desktop Linux
too, unprivileged users can start a new X server and switch virtual
console, even over ssh.

e.g.

$ dbus-send --system --print-reply --dest=org.freedesktop.login1 /org/freedesktop/login1/seat/seat0 
org.freedesktop.login1.Seat.SwitchTo uint32:2

(note: object paths may vary by distro, change the 2 to a different
number if you're already on VT2, or seat0 if you're on a different seat)

If this in fact works over SSH and from a user account different than

Yes, it does.

Why does this functionality even exist?

Because of the same reason why I have dbus on a Spark compute node: systemd :) 

Maybe simply drop the misfeature?

That would break (at least) systemd user sessions I suppose...

Sincerely,
L.


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