[Snort-users] stream5 reassembly and split-tcp handshaking

Joel Esler jesler at ...1935...
Wed Apr 27 08:39:52 EDT 2011


We wrote about this in December of 2009.

http://vrt-blog.snort.org/2009/12/require3whs-and-mystery-of-four-way.html


On Mon, Apr 25, 2011 at 1:55 PM, Kungu Panda <kungupanda at ...11827...> wrote:

> There has been a lot of press recently regarding exploits using tcp
> split handshaking to evading IDS/IPS solutions:
>
> https://www.nsslabs.com/research/network-security/firewall-ngfw/network-firewall-group-test-q2-2011.html
>
> http://www.networkworld.com/news/2011/041211-hacker-exploit-firewalls.html
>     http://nmap.org/misc/split-handshake.pdf
>
> Questions:
>   (a)  How does snort/stream5 handle split-tcp handshakes ?
>   (b)  Does snort maintain correct flow directionality when
> reassembling split-tcp sessions ?
>   (c)  Are there signatures to detect attempts to establish split-tcp
> connections ?
>
> Thanks,
> KPanda
>
>
> ------------------------------------------------------------------------------
> WhatsUp Gold - Download Free Network Management Software
> The most intuitive, comprehensive, and cost-effective network
> management toolset available today.  Delivers lowest initial
> acquisition cost and overall TCO of any competing solution.
> http://p.sf.net/sfu/whatsupgold-sd
> _______________________________________________
> Snort-users mailing list
> Snort-users at lists.sourceforge.net
> Go to this URL to change user options or unsubscribe:
> https://lists.sourceforge.net/lists/listinfo/snort-users
> Snort-users list archive:
> http://www.geocrawler.com/redir-sf.php3?list=snort-users
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://lists.snort.org/pipermail/snort-users/attachments/20110427/b3fe2036/attachment.html>


More information about the Snort-users mailing list