Snort mailing list archives
Re: How to ignore Referrer: header?
From: Brian <bmc () snort org>
Date: Fri, 2 Nov 2001 11:44:29 -0500
According to Williams Jon:
I'm getting a lot of false positives on the WEB-MISC http directory traversal rule. In each one, the "../.." part isn't in the actual request, its in the Referrer: header. Is it possible to write the rule in such a manner that it only triggers on stuff in the request and ignores the rest of the packet? The rule in question is: alert tcp $INTERNAL any -> any 80 (msg:"WEB-MISC http directory traversal"; flags: A+; content: "../"; reference:arachnids,297; classtype:attempted-recon; sid:1113; rev:1;)
Well, if by request you mean URL... Yes. It is possible. But not desired. If you ignore the rest of the packet, you will ignore POST data which may include "../../" Many CGI applications don't care if you are using GET or POST to send of variables, and that would be a very simple way to evade your signatures. -- Why do we have to hide from the police, Daddy? Because we use vi, son. They use emacs. _______________________________________________ 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:
- How to ignore Referrer: header? Williams Jon (Nov 02)
- Re: How to ignore Referrer: header? Brian (Nov 06)