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Re: TCP/BGP vulnerability - easier than you think


From: Petri Helenius <pete () he iki fi>
Date: Fri, 23 Apr 2004 18:45:31 +0300


Leo Bicknell wrote:

I point out NetBSD released this:

ftp://ftp.netbsd.org/pub/NetBSD/security/advisories/NetBSD-SA2004-006.txt.asc

Of interest is this paragraph:

] Additionally, the 4.4BSD stack from which NetBSD's stack is derived, did
] not even check that a RST's sequence number was inside the window. RSTs
] anywhere to the left of the window were treated as valid.

It's a good thing the 4.4BSD stack was unpopular, otherwise it might be
in a lot of programs.

Most code bases fixed this much earlier, like FreeBSD in 1998;
http://www.freebsd.org/cgi/cvsweb.cgi/src/sys/netinet/tcp_input.c.diff?r1=1.80&r2=1.81&f=h

Pete


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