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English Forums => Intrusion Detection and Prevention => Topic started by: monkeydelufy on September 23, 2022, 04:54:07 PM

Title: suricata not blocking nmap scan
Post by: monkeydelufy on September 23, 2022, 04:54:07 PM
hi guys,

using suricata and enable it on wan interface because my opnsense face to public directly using ip public.
now try to scan my ip opnsense using nmap from my pc its scan, no alert from suricata it self, tuning the rules still the same any idea why this happen, i have to protect my opnsense from threat.

still not found solution here any idea how its work or it only work for lan interface...?

opnsense 22.7.4 run on vmware esxi 7
Title: Re: suricata not blocking nmap scan
Post by: cookiemonster on September 23, 2022, 11:03:35 PM
If suricata is monitoring the wan interface, it doesn't see the scan when you do it from your lan. Different interface.
Title: Re: suricata not blocking nmap scan
Post by: monkeydelufy on September 24, 2022, 11:38:02 AM
Quote from: cookiemonster on September 23, 2022, 11:03:35 PM
If suricata is monitoring the wan interface, it doesn't see the scan when you do it from your lan. Different interface.

no i do it from internet not from lan side, my opnsense using public ip so itry to scan using another pc this pc not attached to opnsense network, so i run nmap then no alert found when scan finish.

Title: Re: suricata not blocking nmap scan
Post by: cookiemonster on September 24, 2022, 10:57:51 PM
Emerging-scan.rules is one that has spotted ssh and nmap scans for me (I think).
So you need to verify the rules you have enabled and the type of scan you are performing.
A bit of backgound: https://forum.suricata.io/t/suricata-ids-and-nmap/506
Title: Re: suricata not blocking nmap scan
Post by: monkeydelufy on September 25, 2022, 09:27:29 AM
Quote from: cookiemonster on September 24, 2022, 10:57:51 PM
Emerging-scan.rules is one that has spotted ssh and nmap scans for me (I think).
So you need to verify the rules you have enabled and the type of scan you are performing.
A bit of backgound: https://forum.suricata.io/t/suricata-ids-and-nmap/506

i only use nmap -sV target just like that, and emerging-scan has already rule for that but still not detection event alert not showing up, i don't know what i miss maybe some one has clue for it.

or maybe any other solution for port scanning or something similar.
thanks.
Title: Re: suricata not blocking nmap scan
Post by: siga75 on October 27, 2022, 02:26:21 PM
try a tcpdump on opnsense wan interface to actually see the scan is incoming, don't you have a modem/router in between which only NAT specific ports?
Title: Re: suricata not blocking nmap scan
Post by: monkeydelufy on October 31, 2022, 04:51:27 AM
interface must be in wan because wan interface using public ip address