Re: [Int-area] Kathleen Moriarty's Discuss on draft-ietf-intarea-gre-mtu-04: (with DISCUSS)

[Ronald Bonica <[e-mail]>]

Kathleen,

AFAIK, most IP stacks include code that detects fragmentation overlap attacks. (Do I have that right?)

So, reassembly attacks shouldn't be effective whether reassembly is performed at the GRE egress or the ultimate destination.

If reassembly is performed at the ultimate destination, the two endpoints might be alerted. However, if reassembly is performed at the GRE ingress, the endpoints might never be alerted.

Should we add a paragraph about this in Section 5 (Security Considerations). Or is this just another type of DoS attack, which we have already mentioned?

                                                                                                        Ron


> -----Original Message-----
> From: Kathleen Moriarty [mailto:[e-mail]]
> Sent: Wednesday, May 13, 2015 10:14 PM
> To: The IESG
> Cc: [e-mail]; draft-ietf-intarea-gre-
> [e-mail]; [e-mail]; draft-ietf-intarea-gre-
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> Subject: Kathleen Moriarty's Discuss on draft-ietf-intarea-gre-mtu-04: (with
> DISCUSS)
> 
> Kathleen Moriarty has entered the following ballot position for
> draft-ietf-intarea-gre-mtu-04: Discuss
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> 
> ----------------------------------------------------------------------
> DISCUSS:
> ----------------------------------------------------------------------
> 
> Thanks for your work on this draft, I have a question I'd like to discuss to see
> if another security consideration needs to be added.  This should be very
> quick to resolve.
> 
> Do we need to worry about fragmentation overlap attacks when packets are
> reassembled?  I see that you would not have to worry about it in cases
> where fragmentation is handled at a different layer as is the case with some
> of the methods as it might be addressed at that layer.  Or does it not matter
> as the reassembled packets would be forwarded and the device
> reassembling wouldn't be processing the payload where an exploit could
> avoid detection?
> 
> 
>