From debbugs-submit-bounces@debbugs.gnu.org Mon Nov 23 11:16:14 2020 Received: (at 44808) by debbugs.gnu.org; 23 Nov 2020 16:16:14 +0000 Received: from localhost ([127.0.0.1]:50827 helo=debbugs.gnu.org) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from ) id 1khEVi-0005CQ-0O for submit@debbugs.gnu.org; Mon, 23 Nov 2020 11:16:14 -0500 Received: from dustycloud.org ([50.116.34.160]:57998) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from ) id 1khEVg-0005CJ-Ij for 44808@debbugs.gnu.org; Mon, 23 Nov 2020 11:16:12 -0500 Received: from twig (localhost [127.0.0.1]) by dustycloud.org (Postfix) with ESMTPS id A2D4C266EC; Mon, 23 Nov 2020 11:15:47 -0500 (EST) References: <878sat3rnn.fsf@dustycloud.org> <4383f179-8e3a-7ce6-0fc0-f4cefeaf613e@gmail.com> <20201123044615.13cc0898@riseup.net> User-agent: mu4e 1.4.13; emacs 27.1 From: Christopher Lemmer Webber To: raingloom Subject: Re: bug#44808: Default to allowing password authentication on leaves users vulnerable In-reply-to: <20201123044615.13cc0898@riseup.net> Date: Mon, 23 Nov 2020 11:15:18 -0500 Message-ID: <87r1ok2go9.fsf@dustycloud.org> MIME-Version: 1.0 Content-Type: text/plain X-Spam-Score: -0.0 (/) X-Debbugs-Envelope-To: 44808 Cc: bug-guix@gnu.org, 44808@debbugs.gnu.org X-BeenThere: debbugs-submit@debbugs.gnu.org X-Mailman-Version: 2.1.18 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: debbugs-submit-bounces@debbugs.gnu.org Sender: "Debbugs-submit" X-Spam-Score: -1.0 (-) raingloom writes: > On Mon, 23 Nov 2020 03:32:08 +0100 > Taylan Kammer wrote: > >> On 23.11.2020 00:20, Christopher Lemmer Webber wrote: >> > Okay, I just realized I left a friend vulnerable by guiding them >> > through a Guix graphical install and telling them it would give >> > them a decent setup. They turned on openssh support. >> > >> > Then I realized their config had password-authentication? on. >> > >> > That's unacceptable. We need to change this default. This is >> > known to leave users open to attack, and selecting a password >> > secure enough against brute forcing is fairly difficult, much more >> > difficult than only allowing entry by keys. Plus, few >> > distributions do what we're doing anymore, precisely because of >> > wanting to be secure by default. >> > >> > Yes, I know some people want password authentication on as part of a >> > bootstrapping process. Fine... those users know to put it on. >> > Let's not leave our users open to attack by default though. >> > >> > Happy to produce a patch and change the documentation, but I'd like >> > to hear that we have consensus to make this change. But we should, >> > because otherwise else I think we're going to hurt users. >> >> I think most ideal would be if the user is asked the following two >> questions, with a short explanation of what each means: >> >> - Allow root login via SSH? >> >> - Allow password authentication in SSH? >> >> (I think Debian does this.) >> >> Because as you say, on one hand password authentication in SSH can be >> a security risk. But on the other hand many machines never have >> their SSH port exposed to the Internet, and the intranet is assumed >> to be safe. In those cases it would be an annoyance to have to enable >> it manually. >> >> Both points apply to direct root login as well I think. >> >> Allowing password authentication but disabling root login might also >> be considered safe enough on machines exposed to the Internet, >> because the attacker needs to guess the username as well. Only >> presents a small increase in complexity for the attacker though. >> >> >> - Taylan >> >> >> > > Most people won't know why allowing password authentication is > unsecure. Either it should be worded differently, have a warning, or > not be an option. > > Same goes doubly so for allowing root login. Agreed on both counts.