TCP/BGP vulnerability - easier than you think

Fri Apr 23 15:45:31 UTC 2004

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