From owner-freebsd-questions@FreeBSD.ORG Sat Mar 4 08:00:14 2006 Return-Path: X-Original-To: freebsd-questions@freebsd.org Delivered-To: freebsd-questions@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 762C716A420 for ; Sat, 4 Mar 2006 08:00:14 +0000 (GMT) (envelope-from gabor.kovesdan@t-hosting.hu) Received: from server.t-hosting.hu (server.t-hosting.hu [217.20.133.7]) by mx1.FreeBSD.org (Postfix) with ESMTP id EE46D43D49 for ; Sat, 4 Mar 2006 08:00:13 +0000 (GMT) (envelope-from gabor.kovesdan@t-hosting.hu) Received: from localhost (localhost [127.0.0.1]) by server.t-hosting.hu (Postfix) with ESMTP id 636AE9986DE; Sat, 4 Mar 2006 09:00:12 +0100 (CET) Received: from server.t-hosting.hu ([127.0.0.1]) by localhost (server.t-hosting.hu [127.0.0.1]) (amavisd-new, port 10024) with LMTP id 19488-02; Sat, 4 Mar 2006 09:00:08 +0100 (CET) Received: from [192.168.2.186] (catv-5062e7e3.catv.broadband.hu [80.98.231.227]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by server.t-hosting.hu (Postfix) with ESMTP id B8A8D9986D8; Sat, 4 Mar 2006 09:00:08 +0100 (CET) Message-ID: <44094903.8080006@t-hosting.hu> Date: Sat, 04 Mar 2006 09:00:03 +0100 From: =?ISO-8859-1?Q?K=F6vesd=E1n_G=E1bor?= User-Agent: Mozilla Thunderbird 1.0.6 (Windows/20050716) X-Accept-Language: en-us, en MIME-Version: 1.0 To: Giorgos Keramidas References: <4408D4D3.4030102@t-hosting.hu> <20060304000640.GA26726@flame.pc> In-Reply-To: <20060304000640.GA26726@flame.pc> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-Virus-Scanned: amavisd-new at t-hosting.hu Cc: freebsd-questions@freebsd.org Subject: Re: Where am I? :) X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sat, 04 Mar 2006 08:00:14 -0000 Giorgos Keramidas wrote: >On 2006-03-04 00:44, K?vesd?n G?bor wrote: > > >>Hello, >> >>look at this: >> >>root@server# w >>12:41AM up 82 days, 10:05, 0 users, load averages: 0.00, 0.00, 0.00 >>USER TTY FROM LOGIN@ IDLE WHAT >>root@server# >> >>Where am I? :) I don't know exactly how it happened, but I'll >>investigate, I have an idea and I'll report if I find out. >> >> > >Some programs may tweak wtmp to `hide' users that are actively logged >in. One program that I know can do this is screen(1). Hitting ``^A L'' >here, between successive `w' invocations, I can see this: > >root@flame:/root# w > 2:04AM up 2:10, 1 user, load averages: 0.07, 0.16, 0.19 >USER TTY FROM LOGIN@ IDLE WHAT >root@flame:/root# w > 2:05AM up 2:11, 2 users, load averages: 0.03, 0.14, 0.17 >USER TTY FROM LOGIN@ IDLE WHAT >root pts/0 :0:S.0 2:05AM - w >root@flame:/root# > > > And what do the other logged in users see? With my method I can completely hide, nobody can see me logged in. So I think it might be an opportunity to abusing. I'll send a PR soon, I just wanted to know before if somebody already knows about this trick. Gabor Kovesdan P.S.: It happened on a RELENG_5_3 system via SSH, but I suppose it can be triggered locally.