Antwort: Re: snort sees no fragmented attack

[Holger.Woehle () arcor net]

Hello,
I am using snort 1.8.7 Linux Kernel 2.4.18 Intel Pentium 4 with 256 MByte RAM.
Please see attached snort dump (snort -b ) with the attack dump and the
snort.conf.

with regards
Holger
(See attached file: snort.tar.gz)




Chris Green <cmg () sourcefire com>
09.08.2002 13:28

Bitte antworten an snort-users () lists sourceforge net

An:     Holger Wöhle/PSD/Eschborn/Arcor@Arcor
Kopie:  snort-users () lists sourceforge net
Thema:  Re: [Snort-users] snort sees no fragmented attack



Holger.Woehle () arcor net writes:

> Hello,
> why does snort sees the following attack:
>
> echo "GET /aaaaaaa/aaa/aaaaa/aaaaaaaa/aaaaaaa/bcc/bin/ps" | nc
>
> Snort does not reassemble the packet, and so he does not recognize
> this attack!

Snort Version? OS? Platform? Have you tried against 1.9beta2?

> Can i adjust the preprozessors or the rule to catch this attack ?
>
> alert tcp $EXTERNAL_NET any -> $HTTP_SERVERS $HTTP_PORTS (msg:"WEB-ATTACKS ps
> command attempt"; flags:A+; uricontent:"/bin/ps"; nocase; sid:1328;
> classtype:web-application-attack; rev:4;)

Please send me traffic captures of this attack if you can.  I would
like to see why it's not working in your enviroment.

tcpdump -i eth0 -s 1514 host attackerip -w fragmented-ps.cap
--
Chris Green <cmg () sourcefire com>
A good pun is its own reword.

Attachment: snort.tar.gz
Description: