Subject: Re: [MEXT] MEXT Digest, Vol 22, Issue 23 draftebalard-mext-hld-security-00.txt

From: "Victor Blake" <[email-masked]>
Date: Thu, 30 Apr 2009 17:59:38 -0400

Arnaud,

Your assumption in 4.1 is that the HA relies exclusively on the BU message
from the MN. In fact an HA can rely not only on the BU message itself, but
also the source of the update (BU). That is that the HA, may (not
necessarily but could) know about the Layer 2 source address of MN to
validate the update is coming from the MN it says it is coming from based on
the L3 address. In short, the L2 and L3 address can be correlated.

I believe that there could be other stateful methods as well uses other link
attachment mechanisms such as MIH, DNA, or FMIP in which the sequence in the
state machine would not be valid if such an attack occurred within the
appropriate preceeding and post registration events.

If we try to address the argument beyond just that particular message to
other DoS, I think it is true that there could be cause for concern.
However, regardless of IPsec, Layer 2 DoS attacks would in any event still
be possible. Right ?

-Victor Blake

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Subject: MEXT Digest, Vol 22, Issue 23

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Today's Topics:

   1.  [draft] MIPv6 Home Link Detection Mechanism Security
      considerations (Arnaud Ebalard)

----------------------------------------------------------------------

Message: 1
Date: Thu, 30 Apr 2009 18:37:45 +0200
From: [email-masked] (Arnaud Ebalard)
Subject: [MEXT] [draft] MIPv6 Home Link Detection Mechanism Security
    considerations
To: IETF MEXT WG ML <[email-masked]>
Message-ID: <[email-masked]>
Content-Type: text/plain; charset=us-ascii

Hello,

I have just submitted a draft describing possible attacks (implemented
for demonstration against an existing implementation) associated w/ the
Home Link Detection mechanism and the Home Return procedure.

If some among you find some interest in the topic, I'd be interested by
some feedback (questions, comments). 

Link to the document:

http://www.ietf.org/internet-drafts/draft-ebalard-mext-hld-security-00.txt

Cheers,

a+

IETF I-D Submission Tool <[email-masked]> writes:

> A new version of I-D, draft-ebalard-mext-hld-security-00.txt has been
> successfuly submitted by Arnaud Ebalard and posted to the IETF
> repository. 
>
> Filename:  draft-ebalard-mext-hld-security
> Revision:  00
> Title:         Mobile IPv6 Home Link Detection Mechanism Security
considerations
> Creation_date:     2009-04-30
> WG ID:         Independent Submission
> Number_of_pages: 32
>
> Abstract:
>
> MIPv6 defines the concept of Home Network for a MN, in opposition to
> the foreign network where this entity may find itself.  A ``Home Link
> Detection'' mechanism is also specified to allow the MN to detect
> when it is at home.
>
> MIPv6 specification mandates the use of IPsec for protecting main
> signaling traffic and also defines how IPsec can be used to protect
> data traffic between the MN and its HA.  Even if optional, it is
> expected that many deployments of MIPv6 will use it by default for MN
> which may roam outside a trusted infrastructure (e.g. outside a
> mobile operator network).
>
> When a MN detects it is at home, it is expected to stop IPsec
> protection for data traffic exchanged with its Home Agent.  That
> event is the result of the Home Return procedure, triggered by the
> Home Link Detection mechanism.
>
> This document discusses the possible threats and security impacts
> associated with the use of this insecure NDP-based mechanism as a
> trigger to drop IPsec protection of data traffic for the MN.  It also
> provides some results on the implementation of the attacks against an
> existing MIPv6 module.  Possible solutions are suggested.

------------------------------

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