Re: (DMARC) We've been here before, was Why mailing lists

"Murray S. Kucherawy" <superuser@gmail.com> Fri, 18 April 2014 20:51 UTC

Return-Path: <superuser@gmail.com>
X-Original-To: ietf@ietfa.amsl.com
Delivered-To: ietf@ietfa.amsl.com
Received: from localhost (ietfa.amsl.com [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id 4E3611A0387 for <ietf@ietfa.amsl.com>; Fri, 18 Apr 2014 13:51:13 -0700 (PDT)
X-Virus-Scanned: amavisd-new at amsl.com
X-Spam-Flag: NO
X-Spam-Score: -0.999
X-Spam-Level:
X-Spam-Status: No, score=-0.999 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, FREEMAIL_FROM=0.001, FREEMAIL_REPLY=1, HTML_MESSAGE=0.001, SPF_PASS=-0.001] autolearn=no
Received: from mail.ietf.org ([4.31.198.44]) by localhost (ietfa.amsl.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id AzqyZEz98Pdx for <ietf@ietfa.amsl.com>; Fri, 18 Apr 2014 13:51:12 -0700 (PDT)
Received: from mail-wg0-x22f.google.com (mail-wg0-x22f.google.com [IPv6:2a00:1450:400c:c00::22f]) by ietfa.amsl.com (Postfix) with ESMTP id 0D35A1A02F2 for <ietf@ietf.org>; Fri, 18 Apr 2014 13:51:11 -0700 (PDT)
Received: by mail-wg0-f47.google.com with SMTP id x12so846024wgg.18 for <ietf@ietf.org>; Fri, 18 Apr 2014 13:51:07 -0700 (PDT)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :cc:content-type; bh=xddWEENSoOPZHoAv0PA3IU0FW0al1X3FaNuEV6uxTdk=; b=dVREf/yMf3PQKk/6y/35ZpecYK77/6h8bSmc9C9JJkRcV9fJXI2nOoqMmV5j/Nz+a0 Vo5QCnavMo4D4HeQdUVx0Rav7pUjzD80XpZLccGflmBTqeRleSIWirapEX2iPmggYeUO 3CcC6ospnAOD6KpdcMRo5ZBvmDrNDlXQ96pbPinDEx1SoRMMLv1Nt+RTGqUK+g/gFseo zTnva2KaIfOIj1PIGB7ynoGby3YwD+ziydty52348YrXMk8Zx20bvtqMPiIOvpGxRv5e iLD77jgK/TlScWyyTG+8rU6nvsxM8dEujUTS0F5C7JkmYBylf3CWKULdfk+jKQgG8mt0 RPrA==
MIME-Version: 1.0
X-Received: by 10.180.36.232 with SMTP id t8mr3971323wij.1.1397854267539; Fri, 18 Apr 2014 13:51:07 -0700 (PDT)
Received: by 10.180.211.40 with HTTP; Fri, 18 Apr 2014 13:51:07 -0700 (PDT)
In-Reply-To: <53518F69.90703@gmail.com>
References: <20140417181815.8A5871ACD1@ld9781.wdf.sap.corp> <9451.1397772992@sandelman.ca> <CAL0qLwa0a4nDAdCHkkMJdeemsj+cezcmH3+59CvhF8q7B72ryg@mail.gmail.com> <53518F69.90703@gmail.com>
Date: Fri, 18 Apr 2014 13:51:07 -0700
Message-ID: <CAL0qLwabz5Hi=4zJRW0bcYNCj7dFH6xtK5EyFzRGRhyBmjKAWg@mail.gmail.com>
Subject: Re: (DMARC) We've been here before, was Why mailing lists
From: "Murray S. Kucherawy" <superuser@gmail.com>
To: Brian E Carpenter <brian.e.carpenter@gmail.com>
Content-Type: multipart/alternative; boundary=e89a8f64714b1086c604f7574f96
Archived-At: http://mailarchive.ietf.org/arch/msg/ietf/W2sgN151kNsH7ssCoXD5nVtQu_s
Cc: Michael Richardson <mcr+ietf@sandelman.ca>, Pete Resnick <presnick@qti.qualcomm.com>, John R Levine <johnl@taugh.com>, "ietf@ietf.org" <ietf@ietf.org>
X-BeenThere: ietf@ietf.org
X-Mailman-Version: 2.1.15
Precedence: list
List-Id: IETF-Discussion <ietf.ietf.org>
List-Unsubscribe: <https://www.ietf.org/mailman/options/ietf>, <mailto:ietf-request@ietf.org?subject=unsubscribe>
List-Archive: <http://www.ietf.org/mail-archive/web/ietf/>
List-Post: <mailto:ietf@ietf.org>
List-Help: <mailto:ietf-request@ietf.org?subject=help>
List-Subscribe: <https://www.ietf.org/mailman/listinfo/ietf>, <mailto:ietf-request@ietf.org?subject=subscribe>
X-List-Received-Date: Fri, 18 Apr 2014 20:51:13 -0000

On Fri, Apr 18, 2014 at 1:47 PM, Brian E Carpenter <
brian.e.carpenter@gmail.com> wrote:

> So, if the From says
>
> From: goodguy@yahoo.com <haha@badguy.example.com>
>
> many UAs would show only goodguy@yahoo.com as the sender,
> but badguy could have passed DMARC, no?
>
> This would not exactly enhance goodguy's reputation,
> or Yahoo's for that matter. I realise it isn't the exploit
> that Yahoo is trying to stop, but it suggests to me that
> DMARC is only plugging one small hole in a very leaky dam.
>

Yes indeed.  The DMARC base document discusses this already, by admitting
it's not a problem DMARC can solve right away:

http://tools.ietf.org/html/draft-kucherawy-dmarc-base-04#section-17.4

It's also something that was brought up as a proposed work item for the
IETF.

-MSK