Subject: RE: [Sip] Last Call: DHCPv6 Options for SIP Servers to Proposed Standard

From: "Christian Huitema" <[email-masked]>
Date: Tue, 28 May 2002 08:51:09 -0700

I have a major issue with this spec, namely that the security problems
are not addressed. The security section correctly lists one of the main
security threats, the spoofing of a DHCP server:

   The security considerations in RFC XXXX [1], RFC 3261 [2] and RFC
   3263 [3] apply. If an adversary manages to modify the response from a
   DHCP server or insert its own response, a SIP user agent could be led
   to contact a rogue SIP server, possibly one that then intercepts call
   requests or denies service. A modified DHCP answer could also omit
   host names that translated to TLS-based SIP servers, thus
   facilitating intercept.

This is a very real attack, especially in the deployment phase of IPv6,
when there may not even be an actual DHCPv6 server on the local network.
Think for example of an 802.11 hotpoint, in which any enterprising
attacker could publish his very own DHCPv6 server. Yet, the security
work seems to stop here. There is no attempt at mitigating the attack.
IMHO, we should not publish a spec that open the door for a grave attack
and offers no mitigation.

-- Christian Huitema

> -----Original Message-----
> From: The IESG [mailto:[email-masked]]
> Sent: Wednesday, May 22, 2002 12:21 PM
> Cc: [email-masked]
> Subject: [Sip] Last Call: DHCPv6 Options for SIP Servers to Proposed
> Standard
> 
> 
> The IESG has received a request from the Session Initiation Protocol
> Working Group to consider DHCPv6 Options for SIP Servers
> <draft-ietf-sip-dhcpv6-00.txt> as a Proposed Standard.
> 
> The IESG plans to make a decision in the next few weeks, and solicits
> final comments on this action.  Please send any comments to the
> [email-masked] or [email-masked] mailing lists by June 5, 2002.
> 
> Files can be obtained via
> http://www.ietf.org/internet-drafts/draft-ietf-sip-dhcpv6-00.txt
> 
> 
> 
> 
> 
> _______________________________________________
> Sip mailing list  https://www1.ietf.org/mailman/listinfo/sip
> This list is for NEW development of the core SIP Protocol
> Use [email-masked] for questions on current sip
> Use [email-masked] for new developments on the application of sip

_______________________________________________
Sip mailing list  https://www1.ietf.org/mailman/listinfo/sip
This list is for NEW development of the core SIP Protocol
Use [email-masked] for questions on current sip
Use [email-masked] for new developments on the application of sip

---

From: Henning Schulzrinne <[email-masked]>
Date: Tue, 28 May 2002 12:22:10 -0400

Christian,

thanks for your comment. I'm slightly confused, however, why this 
particular problem is any different for SIP servers than for any other, 
non-SIP server identified by a DHCPv6 server. Also, Section 21 of 
http://www.ietf.org/internet-drafts/draft-ietf-dhc-dhcpv6-25.txt 
addresses this particular issue. Could you clarify your comments in 
these two aspects?

Henning

---

From: "Dean Willis" <[email-masked]>
Date: Tue, 28 May 2002 14:23:13 -0500

Christian wrote:
> I have a major issue with this spec, namely that the security 
> problems are not addressed. The security section correctly 
> lists one of the main security threats, the spoofing of a DHCP server:

Yes, this is a real issue. 

But isn't this sort of a general DHCP problem rather than one specific
to the usage of SIP? 

Do we need to bascially stop using DHCP while working on it, and if so
is this (SIP working group) the right forum to try and tackle that?

--
Dean