Re: [apps-discuss] Review of: draft-ietf-appsawg-malformed-mail-03
"Murray S. Kucherawy" <superuser@gmail.com> Mon, 13 May 2013 06:47 UTC
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Date: Sun, 12 May 2013 23:47:12 -0700
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From: "Murray S. Kucherawy" <superuser@gmail.com>
To: Ned Freed <ned.freed@mrochek.com>
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Cc: Dave Crocker <dcrocker@bbiw.net>, Apps Discuss <apps-discuss@ietf.org>
Subject: Re: [apps-discuss] Review of: draft-ietf-appsawg-malformed-mail-03
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Hi Ned, thanks for your comments. I've worked in most of your suggestions, but have the following to ask further on some of your points: On Mon, May 6, 2013 at 2:14 PM, Ned Freed <ned.freed@mrochek.com> wrote: > Eight-Bit Data (section 8.7) needs a bunch of work, and once again it's a > failure to consider the semantics of where the 8bit shows up. 8bit > appearing in > a header is a very different proposition from 8bit in a body. EAI deserves > a > shout-out in the former case because it's new, and the latter case is now > so > much of a ho-hum for many agents that a recommendation to reject 8bit is > nothing short of silly. > > I'm also far from convinced that rejecting messages because of a single > null is > a good idea. I think a fair assessment of the likely intent in this case > is the > presence of a null or two is simply a message construction error, and > silently > dropping them is a much better bet. > Eight bit data is far from something I'm expert on. Could I ask you to write up a paragraph or three to include here, or replace what's here? > > Header Field Names (section 9.1) is certainly cute, but MIME is actually > quite clear that the first place a boundary can occur is in the following > body, not the associated header. I'm not really comfortable with > this document acting on an assessment of intent of material that is in fact > completely valid. My suggestion is therefore to refrain from talking about > rejecting such messages. > It's a real attack seen in the wild. I see your point about MIME and the location of boundaries, however, so I think this section can just go. > > I'm afraid "Missing MIME-Version Field" (section 9.2) is flat-out > incorrect. > The intent of a message that has a valid content-type and possibly > content-transfer-encoding is pretty darned clear, and perhaps more to the > point, failing to interpret such a message as MIME, given that many other > agents, e.g., metamail, are going to, is exceedingly poor practice from a > security standpoint. > This is also something real I dealt with at a previous employer. More often than not it was seen as part of a spam attack that targeted specific MUAs. I'm fine with removing this section however if the advice is controversial; I don't have access to data to back up how important or useful this change was. > > (If we're up for additions at this late date, it might also be good to add > a > section on how to handle bogus base64 or quoted-printable.) > Yup, we are. Do you have anything specific in mind? -MSK
- [apps-discuss] Review of: draft-ietf-appsawg-malf… Dave Crocker
- [apps-discuss] Review of: draft-ietf-appsawg-malf… Dave Crocker
- Re: [apps-discuss] Review of: draft-ietf-appsawg-… Murray S. Kucherawy
- Re: [apps-discuss] Review of: draft-ietf-appsawg-… Ned Freed
- Re: [apps-discuss] Review of: draft-ietf-appsawg-… Murray S. Kucherawy
- Re: [apps-discuss] Review of: draft-ietf-appsawg-… John Levine
- Re: [apps-discuss] Review of: draft-ietf-appsawg-… Ned Freed
- Re: [apps-discuss] Review of: draft-ietf-appsawg-… John Levine
- Re: [apps-discuss] Review of: draft-ietf-appsawg-… Ned Freed
- Re: [apps-discuss] Review of: draft-ietf-appsawg-… John R Levine
- Re: [apps-discuss] Review of: draft-ietf-appsawg-… Franck Martin
- Re: [apps-discuss] Review of: draft-ietf-appsawg-… Murray S. Kucherawy
- Re: [apps-discuss] Review of: draft-ietf-appsawg-… Murray S. Kucherawy
- Re: [apps-discuss] Review of: draft-ietf-appsawg-… Ned Freed
- Re: [apps-discuss] Review of: draft-ietf-appsawg-… John R Levine
- Re: [apps-discuss] Review of: draft-ietf-appsawg-… Ned Freed
- Re: [apps-discuss] Review of: draft-ietf-appsawg-… Murray S. Kucherawy
- Re: [apps-discuss] Review of: draft-ietf-appsawg-… Ned Freed
- Re: [apps-discuss] Review of: draft-ietf-appsawg-… John R Levine
- Re: [apps-discuss] Review of: draft-ietf-appsawg-… Ned Freed
- Re: [apps-discuss] Review of: draft-ietf-appsawg-… Murray S. Kucherawy
- [apps-discuss] Malformed mail (was Re: Review of:… Ned Freed
- Re: [apps-discuss] Malformed mail (was Re: Review… Barry Leiba
- Re: [apps-discuss] Malformed mail (was Re: Review… John Levine
- Re: [apps-discuss] Malformed mail (was Re: Review… Dave Crocker
- Re: [apps-discuss] Malformed mail (was Re: Review… Murray S. Kucherawy
- Re: [apps-discuss] Malformed mail (was Re: Review… Ned Freed