Messages in this thread | | | Date | Tue, 29 Jun 2004 04:34:11 +0200 | From | Daniel Roesen <> | Subject | Re: TCP-RST Vulnerability - Doubt |
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On Mon, Jun 28, 2004 at 01:22:37PM +0000, Miquel van Smoorenburg wrote: > MD5 protection on BGP sessions isn't very common yet. MD5 uses CPU, > and routers don't usually have much of that. Which means that now an > MD5 CPU attack is possible instead of a TCP RST attack.
Not if the MD5 option is properly implemented - i.e. MD5 hash checking is done AFTER the packet is considered valid in terms of "fitting" sequence number.
> The "TTL hack" solution is safer. Make sure sender uses a TTL > of 255, on the receiver discard all packets with a TTL < 255.
It's a hack, not a solution. A solution works always, not just in some special cases (and given Cisco's implementation, even there is a window which is "too wide open").
As this thread is fairly off-topic on lkml, I suggest moving it to somewhere else... But then again, in the appropriate places, these discussions have already taken place. :-)
Regards, Daniel - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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