Re: [dmarc-ietf] Forensic report loops are a problem
Alessandro Vesely <vesely@tana.it> Thu, 28 January 2021 12:41 UTC
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From: Alessandro Vesely <vesely@tana.it>
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Date: Thu, 28 Jan 2021 13:41:55 +0100
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Subject: Re: [dmarc-ietf] Forensic report loops are a problem
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On Thu 28/Jan/2021 04:17:06 +0100 Steven M Jones wrote: > On 1/27/21 12:47, Murray S. Kucherawy wrote: >> On Wed, Jan 27, 2021 at 12:37 PM John Levine wrote: >> >>> I still don't understand why failure reports about messages that happen >>> to be failure reports are in any way special. >> >> Loop detection in RFC 5321 is a normative MUST because of the obvious >> operational problems it creates. Maybe I'm being thick, but right now I >> don't see how this is different, apart from the fact that each message is >> distinct; you're still causing a problem by turning this on without a care >> in the world about whether two verifiers start spamming each other. > > There's coverage in 7489 Section 7.2 that a domain owner can inadvertently > DDoS themselves via failure reports. And that still surprised many > implementers, even though it seemed obvious to them in retrospect. > > This case is even less obvious, and we still have questions coming in about > it from new implementers. > > I don't think it's a security consideration because it doesn't scale up > the way "ruf" can, so it deserves a brief mention here. But I would > rephrase Ale's last sentence: > > > 3.3. Transport > > Email streams carrying DMARC failure reports MUST conform to the > DMARC mechanism, thereby resulting in an aligned "pass". Special > care must be taken for authentication, as failure to authenticate > failure reports may result in mail loops. These loops can be mitigated > by sending reports from a domain or subdomain that doesn't request > reports, or by performing rate limiting for report receiving mailboxes. I rephrased it further: 3.3. Transport Email streams carrying DMARC failure reports MUST conform to the DMARC mechanism, thereby resulting in an aligned "pass". Special care must be taken of authentication, as failure to authenticate failure reports may result in mail loops. These loops can be mitigated by sending reports from a domain or subdomain that doesn't request reports, or by performing rate limiting especially for failures related to messages received at addresses published in a ruf= tag. Best Ale --
- [dmarc-ietf] Forensic report loops Murray S. Kucherawy
- Re: [dmarc-ietf] Forensic report loops Steven M Jones
- Re: [dmarc-ietf] Forensic report loops Juri Haberland
- Re: [dmarc-ietf] Forensic report loops Дилян Палаузов
- Re: [dmarc-ietf] Forensic report loops Murray S. Kucherawy
- Re: [dmarc-ietf] Forensic report loops Murray S. Kucherawy
- Re: [dmarc-ietf] Forensic report loops Alessandro Vesely
- Re: [dmarc-ietf] Forensic report loops John Levine
- Re: [dmarc-ietf] Forensic report loops Kurt Andersen (b)
- Re: [dmarc-ietf] Forensic report loops Murray S. Kucherawy
- Re: [dmarc-ietf] Forensic report loops Douglas Foster
- Re: [dmarc-ietf] Forensic report loops Дилян Палаузов
- Re: [dmarc-ietf] Forensic report loops are not a … John Levine
- Re: [dmarc-ietf] Forensic report loops are not a … Douglas Foster
- Re: [dmarc-ietf] Forensic report loops are not a … Murray S. Kucherawy
- Re: [dmarc-ietf] Forensic report loops are not a … John R Levine
- Re: [dmarc-ietf] Forensic report loops are a prob… Juri Haberland
- Re: [dmarc-ietf] Forensic report loops are a prob… John Levine
- Re: [dmarc-ietf] Forensic report loops are a prob… Alessandro Vesely
- Re: [dmarc-ietf] Forensic report loops are a prob… John R Levine
- Re: [dmarc-ietf] Forensic report loops are a prob… Alessandro Vesely
- Re: [dmarc-ietf] Forensic report loops are a prob… John R Levine
- Re: [dmarc-ietf] Forensic report loops are a prob… Murray S. Kucherawy
- Re: [dmarc-ietf] Forensic report loops are a prob… John Levine
- Re: [dmarc-ietf] Forensic report loops are a prob… Murray S. Kucherawy
- Re: [dmarc-ietf] Forensic report loops are a prob… John R Levine
- Re: [dmarc-ietf] Forensic report loops are a prob… Steven M Jones
- Re: [dmarc-ietf] Forensic report loops are a prob… Steven M Jones
- Re: [dmarc-ietf] Forensic report loops are a prob… Douglas Foster
- Re: [dmarc-ietf] Forensic report loops are a prob… Alessandro Vesely
- Re: [dmarc-ietf] Forensic report loops are a prob… Murray S. Kucherawy
- Re: [dmarc-ietf] Forensic report loops are a prob… John R Levine
- Re: [dmarc-ietf] Forensic report loops are a prob… Murray S. Kucherawy
- Re: [dmarc-ietf] report floods, not Forensic repo… John R Levine
- Re: [dmarc-ietf] Report bombing is a prolem, Fore… John Levine
- Re: [dmarc-ietf] Report bombing is a prolem, Fore… Douglas Foster
- Re: [dmarc-ietf] Report bombing is a prolem, Fore… Alessandro Vesely
- Re: [dmarc-ietf] Report bombing is a prolem, Fore… John Levine
- Re: [dmarc-ietf] Report bombing is a prolem, Fore… Alessandro Vesely
- Re: [dmarc-ietf] Report bombing is a prolem, Fore… John R Levine
- Re: [dmarc-ietf] Forensic report loops are a prob… Dave Crocker
- Re: [dmarc-ietf] Forensic report loops are a prob… Michael Thomas
- Re: [dmarc-ietf] Forensic report loops are a prob… Dave Crocker
- Re: [dmarc-ietf] Forensic report loops are a prob… Alessandro Vesely
- Re: [dmarc-ietf] Forensic report loops are a prob… Dave Crocker
- Re: [dmarc-ietf] Forensic report loops are a prob… Michael Thomas
- Re: [dmarc-ietf] Forensic report loops are a prob… Michael Thomas
- Re: [dmarc-ietf] Forensic report loops are a prob… Dave Crocker
- Re: [dmarc-ietf] Forensic report loops are a prob… Michael Thomas
- Re: [dmarc-ietf] Forensic report loops are a prob… Dave Crocker
- Re: [dmarc-ietf] Forensic report loops are a prob… Michael Thomas
- Re: [dmarc-ietf] Report bombing is a prolem, Fore… Dotzero
- Re: [dmarc-ietf] Forensic report loops are a prob… John Levine
- Re: [dmarc-ietf] Forensic report loops are a prob… John Levine
- Re: [dmarc-ietf] Forensic report loops are a prob… Dave Crocker
- Re: [dmarc-ietf] Forensic report loops are a prob… Michael Thomas
- Re: [dmarc-ietf] Forensic report loops are a prob… Dave Crocker
- Re: [dmarc-ietf] Forensic report loops are a prob… Dotzero
- Re: [dmarc-ietf] Forensic report loops are a prob… Michael Thomas
- Re: [dmarc-ietf] Forensic report loops are a prob… Michael Thomas
- Re: [dmarc-ietf] Forensic report loops are a prob… Dave Crocker
- Re: [dmarc-ietf] Forensic report loops are a prob… Michael Thomas
- Re: [dmarc-ietf] Forensic report loops are a prob… Dave Crocker
- Re: [dmarc-ietf] DMARC'ed reports, was Forensic r… John R Levine
- Re: [dmarc-ietf] DMARC'ed reports, was Forensic r… Dave Crocker
- Re: [dmarc-ietf] DMARC'ed reports, was Forensic r… Michael Thomas
- Re: [dmarc-ietf] DMARC'ed reports, was Forensic r… Dave Crocker
- Re: [dmarc-ietf] DMARC'ed reports, was Forensic r… Michael Thomas
- Re: [dmarc-ietf] DMARC'ed reports, was Forensic r… Dave Crocker
- Re: [dmarc-ietf] DMARC'ed reports, was Forensic r… Douglas Foster
- Re: [dmarc-ietf] DMARC'ed reports, was Forensic r… Michael Thomas
- Re: [dmarc-ietf] DMARC'ed reports, was Forensic r… Michael Thomas
- Re: [dmarc-ietf] DMARC'ed reports, was Forensic r… Dave Crocker
- Re: [dmarc-ietf] DMARC'ed reports, was Forensic r… Seth Blank
- Re: [dmarc-ietf] Report bombing is a prolem, Fore… Alessandro Vesely
- Re: [dmarc-ietf] DMARC'ed reports, was Forensic r… Alessandro Vesely
- Re: [dmarc-ietf] DMARC'ed reports, was Forensic r… Dave Crocker
- Re: [dmarc-ietf] DMARC'ed reports, was Forensic r… Alessandro Vesely
- Re: [dmarc-ietf] Report bombing is a prolem, Fore… John R Levine