Snort mailing list archives
Re: HTTP Inspect and packet reassembly
From: Yun Zheng Hu <yunzheng.hu () gmail com>
Date: Thu, 28 Oct 2010 15:56:06 +0200
I've also ran intro problems when there are small fragmented tcp packets and using stream5 reassembly, I have posted a question about this earlier on the list: http://seclists.org/snort/2010/q1/587 I've gotten a reply that the developers have a bug open to evaluate this. - Yun On Thu, Oct 28, 2010 at 15:40, L0rd Ch0de1m0rt <l0rdch0de1m0rt () gmail com> wrote:
Hello. I am investigating a situation where TCP streams are being fragmented quite small at the IP layer for some reason (load balancer?) and it seems to be causing problems for some of my rules that leverage HTTP Inspect. From the manual I read this: "The current version of HTTP Inspect only handles stateless processing. This means that HTTP Inspect looks for HTTP fields on a packet-by-packet basis, and will be fooled if packets are not reassembled. This works fine when there is another module handling the reassembly, but there are limitations in analyzing the protocol. Future versions will have a stateful processing mode which will hook into various reassembly modules." OK, so HTTP Inspect is stateless and doesn't reassemble packets. But then there is the sentence, "This works fine when there is another module handling the reassembly, but there are limitations in analyzing the protocol." So my question is, if I also have Stream5 enabled for TCP, is that a sufficient "another module" or are there still "limitations" with the HTTP protocol? Specifically, I have problems with rules that use uricontent and content and need to match across more than one packet. Thanks! -L0rd C. ------------------------------------------------------------------------------ Nokia and AT&T present the 2010 Calling All Innovators-North America contest Create new apps & games for the Nokia N8 for consumers in U.S. and Canada $10 million total in prizes - $4M cash, 500 devices, nearly $6M in marketing Develop with Nokia Qt SDK, Web Runtime, or Java and Publish to Ovi Store http://p.sf.net/sfu/nokia-dev2dev _______________________________________________ Snort-devel mailing list Snort-devel () lists sourceforge net https://lists.sourceforge.net/lists/listinfo/snort-devel
------------------------------------------------------------------------------ Nokia and AT&T present the 2010 Calling All Innovators-North America contest Create new apps & games for the Nokia N8 for consumers in U.S. and Canada $10 million total in prizes - $4M cash, 500 devices, nearly $6M in marketing Develop with Nokia Qt SDK, Web Runtime, or Java and Publish to Ovi Store http://p.sf.net/sfu/nokia-dev2dev _______________________________________________ Snort-devel mailing list Snort-devel () lists sourceforge net https://lists.sourceforge.net/lists/listinfo/snort-devel
Current thread:
- HTTP Inspect and packet reassembly L0rd Ch0de1m0rt (Oct 28)
- Re: HTTP Inspect and packet reassembly Yun Zheng Hu (Oct 28)
- Re: HTTP Inspect and packet reassembly Joel Esler (Oct 28)
- Re: HTTP Inspect and packet reassembly matan monitz (Oct 28)
- Re: HTTP Inspect and packet reassembly Eoin Miller (Oct 28)
- Re: HTTP Inspect and packet reassembly Joel Esler (Oct 28)
- Re: HTTP Inspect and packet reassembly Matt Olney (Oct 28)
- Re: HTTP Inspect and packet reassembly L0rd Ch0de1m0rt (Oct 29)
- Re: HTTP Inspect and packet reassembly Joel Esler (Oct 29)
- Re: HTTP Inspect and packet reassembly Eoin Miller (Oct 31)
- Re: HTTP Inspect and packet reassembly Joel Esler (Oct 31)
- Re: HTTP Inspect and packet reassembly matan monitz (Oct 28)
- Re: HTTP Inspect and packet reassembly Yun Zheng Hu (Oct 29)