RE: Bittorrent Data Port Probe

From: Paul Melson (pmelson@gmail.com)
Date: Fri Aug 24 2007 - 13:28:12 EDT


On 8/23/07, John Lampe <jwlampe@tenablesecurity.com> wrote:
> I know for a *fact* that it can be passively detected :-) We wrote a
> bunch of passive detection plugins for our PVS product.

Yup. Snort's had signatures for it for a couple years. ;-)

> port = 6881; # bittorrent
> #port = 63180; # mutorrent
>
> for (i=0; i<95; i++) {init = string(init, raw_string(rand() % 256));}
>
> for (i=0; i<96; i++) {req = string(req, raw_string(rand() % 256));}

I can't seem to recreate this:

$ perl -e 'for (my $i=0; $i <= 90; $i++) {print chr(int(rand 255));}' | nc
-v localhost 6881
Connection to localhost 6881 port [tcp/*] succeeded!
$ perl -e 'for (my $i=0; $i <= 95; $i++) {print chr(int(rand 255));}' | nc
-v localhost 6881
Connection to localhost 6881 port [tcp/*] succeeded!
$ perl -e 'for (my $i=0; $i <= 96; $i++) {print chr(int(rand 255));}' | nc
-v localhost 6881
Connection to localhost 6881 port [tcp/*] succeeded!
$ perl -e 'for (my $i=0; $i <= 100; $i++) {print chr(int(rand 255));}' | nc
-v localhost 6881
Connection to localhost 6881 port [tcp/*] succeeded!
$ perl -e 'for (my $i=0; $i <= 1000; $i++) {print chr(int(rand 255));}' | nc
-v localhost 6881
Connection to localhost 6881 port [tcp/*] succeeded!

If you care, the client is bittorrent-curses 4.4.0 on OpenBSD (it's what I
had quick access to). I haven't tried your nasl code in Nessus, so maybe
I'm missing something. But if I understand your previous post, this should
elicit some response from a seeding client, and in my case it doesn't.

PaulM

------------------------------------------------------------------------
This list is sponsored by: Cenzic

Need to secure your web apps NOW?
Cenzic finds more, "real" vulnerabilities fast.
Click to try it, buy it or download a solution FREE today!

http://www.cenzic.com/downloads
------------------------------------------------------------------------



This archive was generated by hypermail 2.1.7 : Sat Apr 12 2008 - 10:58:03 EDT