> -----Original Message-----
> From: [email protected] [mailto:[email protected]] 
> On Behalf Of Steve Atkins
> Sent: Monday, October 25, 2010 12:54 PM
> To: IETF DKIM WG
> Subject: Re: [ietf-dkim] Proposal for new text about multiple header issues
> 
> > I'd strike "during a replay attack" because, as some have noted, the
> > attack can be constructed deliberately on an original message.
> 
> The real risk here is that someone can present a message as signed by
> someone trustworthy that has content different to that which was
> provided by the trusted signer. If the entity adding the additional
> content is the original signer, it may be a message composition bug,
> but it's not really any sort of attack on DKIM.
> 
> Striking "replay attack" might make it less clear what the actual risk
> is, rather than more clear.
> 
> ("... can be abused, e.g. during a replay attack, by adding ..." ?)

Isn't the more interesting attack a signature from some throwaway domain that 
covered a matching From: but also contained a From: indicating some high-value 
phish target?

> > It's also not specific to MUAs.  Filtering agents can be similarly
> > duped.
> 
> They can, yes, though I'm not sure that's needed to explain why this
> may be a bad thing to allow.

Focusing on the MUA case might inadvertently suggest to implementers of other 
components that this is not a concern for them.


_______________________________________________
NOTE WELL: This list operates according to 
http://mipassoc.org/dkim/ietf-list-rules.html

Reply via email to