[Snort-users] shellcode_ports

Gentoo-Wally gentoowally at ...11827...
Wed May 24 08:36:03 EDT 2006


Is there a better way to define SHELLCODE_PORTS other than !80?

All the sig's using this var show..

$EXTERNAL_NET $SHELLCODE_PORTS -> $HOME_NET  any

If we really want to look for shellcode to any port from every port
but 80 then why not on 80 also? Or why not also exclude 8080 and 443
(or any other encrypted ports like 22)

Assuming this works the same way as HTTP_PORTS...

var SHELLCODE_PORTS !80
var SHELLCODE_PORTS !8080
var SHELLCODE_PORTS !443
var SHELLCODE_PORTS !22

Or even
var SHELLCODE_PORTS !80
var SHELLCODE_PORTS !8080
var SHELLCODE_PORTS !443
var SHELLCODE_PORTS !22
var EXCLUDE !22
var EXCLUDE !443

and rewriting these sigs with oinkmaster to be...

$EXTERNAL_NET $SHELLCODE_PORTS -> $HOME_NET  $EXCLUDE

Since looking for shellcode on encrypted traffic is kind of a waste of
time, right?

What are others doing for this?

This brings up another point...

the snort.conf shows defining these port options for multiple ports like this...

## var HTTP_PORTS 80
## include somefile.rules
## var HTTP_PORTS 8080
## include somefile.rules

is specifying an include after each port defined necessary or is the
following adequate?

var HTTP_PORTS 80
var HTTP_PORTS 8080
...
include somefile.rules

using snort 2.4.4

Thx,
Wally




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