Re: [dmarc-ietf] Tickets 98 and 99 -- fake reports are not a problem and if they were authentication would not help

[Michael Thomas <[e-mail]>]

But just as an example, suppose I'm trying to get to a position to use 
p=reject, but some bad actor doesn't want me to do that so they can keep 
phishing me. All they have to do is keep sending forged message reports 
from gmail which makes me think I've got a problem. Seriously, this is 
not rocket science.

Mike

On 1/25/21 9:25 AM, Seth Blank wrote:
> Mike, how do you believe DMARC reports are consumed and utilized? I 
> think you have a misunderstanding here which is why you're going down 
> this path and everyone else is pushing back.
>
> On Mon, Jan 25, 2021 at 9:22 AM Michael Thomas <[e-mail] 
> <mailto:[e-mail]>> wrote:
>
>     Taking in information from unauthenticated sources and acting on
>     it is an operational problem per se. Have we learned nothing in
>     the last 30 years?
>
>     Mike
>
>     On 1/25/21 9:19 AM, Seth Blank wrote:
>>     What operational problem are we solving here? Absent evidence of
>>     a problem and strong consensus on the solution, let's close these
>>     tickets and move on.
>>
>>     On Mon, Jan 25, 2021 at 9:10 AM Douglas Foster
>>     <[e-mail]
>>     <mailto:[e-mail]>> wrote:
>>
>>         Since the status quo is unauthenticated, I wonder if adding a
>>         signing requirement will help.
>>         Will recipients discad unsigned messages, or accept whatever
>>         is available to maximize their information capture?  I
>>         suspect they will conrinye to accept everything.
>>
>>         I think we would need an identified threat before recipients
>>         would be motivated to discard.
>>
>>         But what about John's problems with receiving reports that
>>         should not have gone to him?   I did not understand the root
>>         cause, but I would hope there is something that can be done.
>>         Would signing help receiving sites, those with less
>>         sophistication than he has, be able to sort out noise more
>>         effectively?
>>
>>
>>         On Mon, Jan 25, 2021, 11:51 AM Michael Thomas <[e-mail]
>>         <mailto:[e-mail]>> wrote:
>>
>>
>>             On 1/25/21 8:44 AM, Todd Herr wrote:
>>>             On Mon, Jan 25, 2021 at 10:18 AM Michael Thomas
>>>             <[e-mail] <mailto:[e-mail]>> wrote:
>>>
>>>
>>>                 The main thing I've learned over the years of
>>>                 dealing with security is to not underestimate what a
>>>                 motivated attacker can do. Your imagination is not
>>>                 the same as their imagination. Closing #98 in
>>>                 particular is absolutely ridiculous: the report
>>>                 should already have a DKIM signature or SPF so it's
>>>                 just a matter of making sure its valid. Why would
>>>                 you *not* want to insure that? The amount of
>>>                 justification for *not* having the receiver
>>>                 authenticate it is a mountain. The amount of effort
>>>                 to authenticate it is trivial for mail. Levine's
>>>                 dismissal of security concerns because he has
>>>                 anecdotal "evidence" from a backwater domain carries
>>>                 no weight at all.
>>>
>>>
>>>             That's all well and good, but you haven't answered the
>>>             question I asked.
>>>
>>>             What threats do you have in mind? Put another way, how
>>>             do you envision an attacker exploiting the lack of
>>>             authentication in a DMARC report to his or her gain?
>>>
>>             No, sorry, the onus is on the people who don't think it
>>             can be gamed. A bald assertion that it can't be gamed is
>>             very unconvincing. You need to lay out a miles long case
>>             for why it cannot be gamed. And to what end? #98 has a
>>             simple piece of text that should be added to DMARC to
>>             eliminate the possibility of forgery. You'd need a 10
>>             page threat I-D to explain why it's not necessary. What
>>             is the point of that? For email, it's trivial to prevent
>>             forgeries. Why would anybody argue against that?
>>
>>             Mike
>>
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>>
>>
>>     -- 
>>     *Seth Blank*| VP, Standards and New Technologies
>>     *e:*[e-mail] <mailto:[e-mail]>
>>     *p:*415.273.8818
>>
>>
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>
>
> -- 
> *Seth Blank*| VP, Standards and New Technologies
> *e:*[e-mail] <mailto:[e-mail]>
> *p:*415.273.8818
>
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