[OSPF] Dropping malformed LSAs (was: OSPF - Owning the Routing Table Attack)

David Lamparter <equinox@diac24.net> Sun, 04 August 2013 13:06 UTC

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Date: Sun, 4 Aug 2013 15:06:03 +0200
From: David Lamparter <equinox@diac24.net>
To: Glen Kent <glen.kent@gmail.com>
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Subject: [OSPF] Dropping malformed LSAs (was: OSPF - Owning the Routing Table Attack)
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On Fri, Aug 02, 2013 at 10:11:01PM +0530, Glen Kent wrote:
> Does anybody have details on what this OSPF vulnerability is?
> https://www.blackhat.com/us-13/briefings.html#Nakibly

As people may have noticed by now (the embargo on providing details has
expired as the talk was presented), this issue consists of Router LSAs
where the Router ID is different from the Link State ID.  As such, this
attack is implementable from any router in an OSPF area against any
other router in the OSPF.

(Quite honestly, IMHO this is seriously far fetched.  If your control
plane got compromised this far you have other problems.)

While Quagga is unaffected by this, we've implemented a warning.  We're
also considering dropping the LSA outright, but I'm somewhat split on
that (tilted towards dropping).  I'd be interested if the WG has
comments on that?