Nmap Scan Output - PIX firewall shows ports open even when disabled?

["erisk" <erisk () iinet net au>]

Hi all,

I have had this on a few instances and I was wondring if anyone can verify
if this is something other people have found when scanning PIX's or web
servers in the DMZ..

Firstly I scanned using the normal sS routine and ports were found closed.
Following that I preceded to scan without pinging the host and the output is
below:

nmap -P0 XXX.XXX.XXX.XX

Starting nmap V. 3.00 ( www.insecure.org/nmap/ )
Interesting ports on XXXX (X.X.X.X):
(The 1596 ports scanned but not shown below are in state: filtered)
Port       State       Service
389/tcp    open        ldap
1002/tcp   open        unknown
1720/tcp   open        H.323/Q.931

I have confirmed with the rulebase and the none of the ports that are open
are defined in the rule base and everything elese is still explictly denied
(even though PIX does it by default) by a deny IP rule. Also the majority of
fixup protocols have been disbaled (except HTTP, SMTP).

Also when I scan web servers behind the firewall with this option it still
has the same ports open + HTTP and HTTPS...

This is the third time I have had this output when using this no ping host
option, so has anyone found the similar outputs? Could this be a common way
to commonly identify PIX firewalls? Is there an advisory for this? And are
there any workarounds so these ports are not shown on the no ping scan?

Regards,
Trev



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