topic Re: Expected behaviour for Null, FIN and XMAS scans in General Topics

Expected behaviour for Null, FIN and XMAS scans

nicholasstone — Tue, 18 Apr 2017 01:34:22 GMT

Running through a few very basics tests to prove Zone Protection etc with a customer, what is the expected default behaviour for reconaissance scans such as Null, FIN and XMAS scans?

Currently I can get the following nmap commands to run without issue and no logs beyond ping or icmp.

nmap -sX

nmap -sF

nmap -sN

What would be the appropriate measure to block/alert these? assuming there is a cryptic box top tick under the ZPP dialogs

Re: Expected behaviour for Null, FIN and XMAS scans

reaper — Tue, 18 Apr 2017 13:31:33 GMT

'rogue' flags are removed from packets without needing a Zone Protection Profile in place

Re: Expected behaviour for Null, FIN and XMAS scans

nicholasstone — Tue, 18 Apr 2017 22:49:40 GMT

It's probably somewhere subtle, but is this documented anywhere?

Re: Expected behaviour for Null, FIN and XMAS scans

nicholasstone — Wed, 19 Apr 2017 00:05:28 GMT

Confirming that a packet capture on the "victim" machine shows no packets with TCP flags for ACK, FIN or PSH set when performing Christmas Tree. Packet capture on Firewall at stage "Receive" shows that the packets are indeed received by the firewall.

nmap command used:

nmap -sX -v [host]