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Vinícius Valente
Asked: 2020-01-08 07:02:13 +0800 CST

Is there a way to force UFW firewall accept only connections from local network? Better practices?

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I was trying to setup the UFW firewall to allow my smartphone connecting my Ubuntu with KDE-connect and I saw this recommended configuration for UFW in KDE community (https://community.kde.org/KDEConnect):

sudo ufw allow 1714:1764/udp
sudo ufw allow 1714:1764/tcp

But this raise me some question around this... Can this configuration be considered a vulnerability? Can someone outside my local network use these ports to get access to my data?

So I thouhgt to use this configuration instead:

sudo ufw allow proto tcp from 192.168.0.0/24 to any port 1714:1764
sudo ufw allow proto udp from 192.168.0.0/24 to any port 1714:1764

Is this a better practice to avoid a vulnerability and force UFW to accept only connections within my local network?

security networking firewall ufw kde-connect

1 Answers

  1. Hardly, but it depends how your environment is set up. user535733 already gave a nice example.
    Better practice - it can be if you like or need strict approach.
    You can also look at your Ethernet interface:

    ip -c a

    Let’s say it is eth0.
    So then you can do something like this:

    sudo ufw allow in on eth0 proto tcp from 192.168.1.0/29 to any port 1714:1764

    You can also check a range of given IP addresses to see if they do fit your needs:

    ipcalc 192.168.1.0/29
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