Re: IGNORING SSH CONNECTION USES ARP CACHE POISSONING

[Hugo van der Kooij <hvdkooij () vanderkooij org>]

On Tue, 9 May 2006 king_purba () yahoo co uk wrote:

> We know that tcp connection will close by sending RST flag.
> I try to connect to my openssh server on
> slackware 10 from my computer fedora core 4. Then using an
> openbsd 3.7, that had same network with slackware n fedora,
> try to overwrite ARP cache on my fedora core 4. After arp
> cache has been overwriten, all packet from fedora core 4
> to slackware 10 is ignored. May be this problem is not only
> on ssh but on other tcp protocol.

This is an issue with IP in general. Anyone who can spoof ARP entries in a
network can pretty much do anything they want on you LAN.

If there is a flaw then it is a flaw in your switch not protecting you
from such an ARP spoofing issue. There are tools to detect it at host
level and warn you about it.

Further recommended reading:
http://www.codeproject.com/internet/winarpspoof.asp
http://www.l0t3k.org/security/docs/arp/

And I'm sure there must be a load of other documents out there. These were
picked after a 5 second search with google.

I'm a bit puzzled why this message was in fact released on bugtraq as it
adds nothing new to the arp spoofing story.

Hugo.

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        hvdkooij () vanderkooij org             http://hvdkooij.xs4all.nl/
                Don't meddle in the affairs of magicians,
                for they are subtle and quick to anger.