Snort mailing list archives
Bug report - no content match on http_inspect port
From: elof () sentor se
Date: Fri, 4 Mar 2011 15:57:06 +0100 (CET)
Snort doesn't trigger alerts on traffic if that port is included in the
http_inspect ports.
Example:
A basic rule:
alert tcp any 3128 -> any any (msg:"foo"; flow:from_server,established;
content:"login|3A| root"; sid:1234; rev:1;)
If the snort.conf contain this http_inspect configuration, sid:1234 will
never trigger even if a packet is seen containing "login: root" from port
3128. Bug!
preprocessor http_inspect_server: server default profile all ports { 80
3128 8080 } oversize_dir_length 500 no_alerts
If I remove port 3128 from the configuration and try again, I get an
alert.
preprocessor http_inspect_server: server default profile all ports { 80
8080 } oversize_dir_length 500 no_alerts
I tested it using this simple setup:
Server: echo "login: root" | nc -l 3128
Client: nc serverip 3128
When the client connect, I get a logged event using the second config.
When the client connect, I don't get any event using the first config.
This is reproduceable.
Could it be that http_inspect tries to normalise the string "login: root"
and by doing so breaks it, so that there are no matches?
/Elof
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Current thread:
- Bug report - no content match on http_inspect port elof (Mar 04)
- Re: Bug report - no content match on http_inspect port Joel Esler (Mar 04)
- Re: Bug report - no content match on http_inspect port elof (Mar 04)
- Re: Bug report - no content match on http_inspect port Joel Esler (Mar 04)
- Re: Bug report - no content match on http_inspect port elof (Mar 04)
- Re: Bug report - no content match on http_inspect port Ryan Jordan (Mar 04)
- Re: Bug report - no content match on http_inspect port elof (Mar 07)
- Re: Bug report - no content match on http_inspect port elof (Mar 04)
- Re: Bug report - no content match on http_inspect port Joel Esler (Mar 04)
