[11440] in bugtraq
Re: XDM Insecurity revisited
daemon@ATHENA.MIT.EDU (Martin Schulze)
Fri Aug 20 17:17:37 1999
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Message-Id:  <19990819100710.J28824@finlandia.infodrom.north.de>
Date:         Thu, 19 Aug 1999 10:07:11 +0200
Reply-To: Martin Schulze <joey@infodrom.north.de>
From: Martin Schulze <joey@FINLANDIA.INFODROM.NORTH.DE>
X-To:         BUGTRAQ@SECURITYFOCUS.COM
To: BUGTRAQ@SECURITYFOCUS.COM
In-Reply-To:  <19990818122620.A16339@luna.theo2.physik.uni-stuttgart.de>; from
              Jochen Bauer on Wed, Aug 18, 1999 at 12:26:20PM +0200
Jochen Bauer wrote:
> On Wed, 26 Nov 1997 Eric Augustus (augustus@stic.net) posted a message
> on BUGTRAQ about the fact, that the default Xaccess file allows XDMCP
> connections from any host. As you know, this can be used to get a
> login screen on any host and therefore get around access control
> mechanisms like tcpwrapper and root login restriction to the console.
I'm not sure if I have understood your considerations.  The intruder
still needs an account on the local host, so it is as insecure as
allowing telnet access to your host.  Or not?
However, I agree that XDMCP should be restricted to the local LAN
by default.
Tcpwrappers are no major security improvement.  It's just a little
bit restictive.  You'll still have to manually add host that you
permit or deny access to your services.  The paranoid flag does
not keep hackers off of your host but people who are beaten with
dumb admins who don't care about reverse DNS.
Regards,
	Joey
--
GNU does not eliminate all the world's problems, only some of them.
                                                -- The GNU Manifesto