Re: possible bug, nmap v7.40

[Daniel Miller <bonsaiviking () gmail com>]

Yes, I have seen this happening. It's slowing down scans a lot, and I
suspect it has something to do with the conntrack module that is used for
the "ESTABLISHED" and "RELATED" matches, but I can't figure out what the
cause is. If you do a very slow scan (-T2) nothing goes wrong, so it's a
rate limit of some sort. We really need to figure out what the problem is
and how to work around it!

Dan

On Wed, Feb 1, 2017 at 4:33 PM, cyb <cg.venus () gmail com> wrote:

> Hi,
>
> I'm experiencing a problem using nmap (v7.40) with iptables on kali
> (Debian 4.8.15-1kali1 (2016-12-23) x86_64 GNU/Linux).
>
> I have messages like:
> *sendto in send_ip_packet_sd: sendto(4, packet, 44, 0, 45.33.32.156, 16)
> => Operation not permitted*
> if my firewall is activated.
>
> I'm using VPN with OpenVPN and nmap works fine after startup with VPN ==
> on and iptabels == off, but if I'm activating firewall (script vpnfw.sh
> attached) nmap is sending error messages. I read about it that you need to
> allow INVALID packets and I'm doing that but it doesn't help. But what is
> more weired, even after I reset firewall (script fwreset.sh attached) it's
> still showing me error messages. I tried to restart network services etc,
> nothing helps, only PC restart.
>
> Even after I disconnect from VPN, flush iptables, restart wlan0 interface
> and network-manager, even after this nmap still sends error messages.
>
> So, such scenario:
>
> - PC start up.
> - VPN=off,
> - Firewall disabled, iptables=off.
> - Nmap *OK*.
> - Enabling VPN=on.
> - Nmap *OK*.
> - Firewall enabling, iptables=on.
> - Nmap *FAIL*.
> - Firewall disable, iptables=off.
> - Nmap *FAIL*.
> - Disabling VPN=off
> - Nmap *FAIL*.
> - Try restart all network services.
> - Nmap *FAIL*.
> - PC restart.
> - Nmap *OK*.
>
> Regards
>
>
> _______________________________________________
> Sent through the dev mailing list
> https://nmap.org/mailman/listinfo/dev
> Archived at http://seclists.org/nmap-dev/
_______________________________________________
Sent through the dev mailing list
https://nmap.org/mailman/listinfo/dev
Archived at http://seclists.org/nmap-dev/