From owner-freebsd-stable  Fri Jan 21 15:58:30 2000
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From: Darren Reed <avalon@coombs.anu.edu.au>
Message-Id: <200001212358.KAA15748@cairo.anu.edu.au>
Subject: Re: bugtraq posts: stream.c - new FreeBSD exploit?
To: kraemer@u.washington.edu (Brian Kraemer)
Date: Sat, 22 Jan 2000 10:58:28 +1100 (Australia/NSW)
Cc: avalon@coombs.anu.edu.au (Darren Reed),
	freebsd-security@FreeBSD.ORG, freebsd-stable@FreeBSD.ORG
In-Reply-To: <Pine.A41.4.10.10001210852260.109950-100000@mead2.u.washington.edu> from "Brian Kraemer" at Jan 21, 2000 08:55:32 AM
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In some mail from Brian Kraemer, sie said:
> 
> On Fri, 21 Jan 2000, Darren Reed wrote:
> 
> > btw, I think the better way to write the 3 rules is:
> > 
> > block in quick proto tcp from any to any head 100
> > pass in quick proto tcp from any to any flags S keep state group 100
> > pass in all
> 
> If I'm not mistaken, this ruleset (and no other rules) will also
> effectively block any outgoing TCP sessions initiated from this machine.
> The machine will send a SYN, and then get blocked because the input rules
> never saw an incoming SYN to start keeping state.
> 
> I assume a rule that keeps state on the outgoing would fix this?

Yes.  I forgot about that :-)
pass out proto tcp from any to any flags S keep state
would be required also.

Darren


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