netdiscover's network access not detected or blocked

[VorpalBlade]

Please, check the FAQ and Known Problems pages before creating the bug report:

https://github.com/evilsocket/opensnitch/wiki/FAQs

GUI related issues: https://github.com/evilsocket/opensnitch/wiki/GUI-known-problems

Daemon related issues:

• Run opensnitchd -check-requirements to see if your kernel is compatible.: All green
• https://github.com/evilsocket/opensnitch/wiki/daemon-known-problems

Describe the bug It seems netdiscover passes under the radar of opensnitch. I'm not actually sure what type of sockets netdiscover uses, so I don't know if this is expected.

Include the following information:

• OpenSnitch version. 1.6.5.1-1 (installed from distro + ebpf from AUR)
• OS: Arch Linux
• Version: rolling release
• Window Manager: KDE Plasma 6.1.4
• Kernel version: Linux athena 6.10.8-zen1-1-zen #1 ZEN SMP PREEMPT_DYNAMIC Wed, 04 Sep 2024 15:18:31 +0000 x86_64 GNU/Linux

To Reproduce Steps to reproduce the behavior:

1. Install netdiscover: pacman -S netdiscover
2. Enable opensnitch and verify it works with "normal" programs (getting popups etc)
3. Run netdiscover.
4. OpenSnitch doesn't detect or block netdiscover's network access. And netdiscover works as if opensnitch wasn't there.

Post error logs: I don't see any relevant error logs in this case.

Expected behavior (optional) Netdiscover shouldn't be able to bypass opensnitch.

Screenshots If applicable, add screenshots or videos to help explain your problem. It may help to understand the issue much better.

Additional context Add any other context about the problem here.

[VorpalBlade]

Also tried this on a stock Ubuntu 24.04 system (kernel 6.8.0-41-generic) with the exact result: netdiscover bypasses opensnitch.

[VorpalBlade]

I straced the netdiscover and it seems to use many types of sockets: AF_PACKET, AF_NETLINK, AF_BLUETOOTH (???). All of them are SOCK_RAW.

The strange thing then is that netdiscover gets past, while nmap gets blocked?

[gustavo-iniguez-goya]

Hi @VorpalBlade ,

Yeah, it seems to use RAW sockets to send ARP requests: netdiscover - active/passive ARP reconnaissance tool

We don't work at that level.