Snort mailing list archives
Re: Content not being detected
From: Matt Olney <molney () sourcefire com>
Date: Tue, 10 Feb 2009 08:52:38 -0500
Well there are a couple of things to consider. First, you most likely don't have to worry about stream reassembly. I would anticipate a single pcap to handle the post and the uri. Second, without a pcap to work with, I would say you first need to find out which part of your rule is not firing. When troubleshooting rules, and I really get hung up, I usually do something like this: alert tcp $EXTERNAL_NET any -> $HOME_NET $HTTP_PORTS (msg:"ALERT - POST - Execution of asp"; flow:to_server,established; uricontent:"/ab/dir1/"; nocase; uricontent:".asp"; nocase; content: "POST"; depth: 4; nocase; classtype:web-application-activity; sid:1000004; rev:2;) alert tcp $EXTERNAL_NET any -> $HOME_NET $HTTP_PORTS (msg:"ALERT - POST - Execution of asp - no POST"; flow:to_server,established; uricontent:"/ab/dir1/"; nocase; uricontent:".asp"; nocase; classtype:web-application-activity; sid:1000005; rev:2;) alert tcp $EXTERNAL_NET any -> $HOME_NET $HTTP_PORTS (msg:"ALERT - POST - Execution of asp - no POST, no asp"; flow:to_server,established; uricontent:"/ab/dir1/"; nocase; classtype:web-application-activity; sid:1000006; rev:2;) alert tcp $EXTERNAL_NET any -> $HOME_NET $HTTP_PORTS (msg:"ALERT - POST - Execution of asp - no flow, no POST, no asp"; uricontent:"/ab/dir1/"; nocase; classtype:web-application-activity; sid:1000007; rev:2;) alert tcp any any -> any any (msg:"ALERT - POST - Execution of asp - any any no POST, no asp"; flow:to_server,established; content:"/ab/dir1/"; nocase; classtype:web-application-activity; sid:1000008; rev:2;) This set of rules should at least point towards what the issue is. Run these, and look at what alerts. That should tell you where the problem is, and we can move on. Also, know that there is an update to 2.8.3.1, although nothing in there should address this issue, it is important to stay current. Let me know how that works, Matt On Mon, Feb 9, 2009 at 10:39 PM, Matt Olney <molney () sourcefire com> wrote:
I'm not at work, but try changing the POST/depth combo to: content:"POST"; http_method; nocase; Matt On Mon, Feb 9, 2009 at 9:55 PM, Jimmy Tharel <jtharel () yahoo com> wrote:I recently upgraded from Snort 2.6 to 2.8.3.1 and the following rule has quit working. alert tcp $EXTERNAL_NET any -> $HOME_NET $HTTP_PORTS (msg:"ALERT - POST - Execution of asp"; flow:to_server,established; uricontent:"/ab/dir1/"; nocase; uricontent:".asp"; nocase; content: "POST"; depth: 4; nocase; classtype:web-application-activity; sid:1000004; rev:2;) It worked just fine in 2.6 but for whatever reason does not work in 2.8.3.1. My http_inspect section of my snort.conf is the same in both versions: preprocessor http_inspect: global \ iis_unicode_map unicode.map 1252 preprocessor http_inspect_server: server default \ profile all ports { 80 8080 8180 } oversize_dir_length 500 Could it be the difference between the Stream4 and Stream5 preprocessor? My Stream5 is configured with the defaults and the setup is: preprocessor stream5_global: max_tcp 8192, track_tcp yes, \ track_udp no preprocessor stream5_tcp: policy first, use_static_footprint_sizes I've read over the Stream5 README but I don't see anything that would be causing that rule not to work. I've played with the max_tcp and memcap settings but to no avail. Can anybody help me? Thanks! ------------------------------------------------------------------------------ Create and Deploy Rich Internet Apps outside the browser with Adobe(R)AIR(TM) software. With Adobe AIR, Ajax developers can use existing skills and code to build responsive, highly engaging applications that combine the power of local resources and data with the reach of the web. Download the Adobe AIR SDK and Ajax docs to start building applications today-http://p.sf.net/sfu/adobe-com _______________________________________________ Snort-users mailing list Snort-users () 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
------------------------------------------------------------------------------ Create and Deploy Rich Internet Apps outside the browser with Adobe(R)AIR(TM) software. With Adobe AIR, Ajax developers can use existing skills and code to build responsive, highly engaging applications that combine the power of local resources and data with the reach of the web. Download the Adobe AIR SDK and Ajax docs to start building applications today-http://p.sf.net/sfu/adobe-com _______________________________________________ Snort-users mailing list Snort-users () 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
Current thread:
- Content not being detected Jimmy Tharel (Feb 09)
- Re: Content not being detected Matt Olney (Feb 09)
- Re: Content not being detected Matt Olney (Feb 10)
- Re: Content not being detected Matt Olney (Feb 09)