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Faruk
Faruk

Posted on • Originally published at Medium

Why You Should Never Trust Default Configurations on a Fresh Linux Install | by Faruk Ahmed | Jul, 2025

#fresh #install #bash #default

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Why You Should Never Trust Default Configurations on a Fresh Linux Install

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Intro

Many admins assume a fresh install of Ubuntu or Red Hat is secure out of the box. I used to think the same — until I realized how much was silently exposed. Default configurations are designed for usability, not security. In this blog, I’ll show you what I now check and lock down immediately after every Linux install.

1. Unnecessary Services Are Running

Fresh installs often start services you don’t need — like Bluetooth, cups, or even Avahi (zeroconf).

🔍 Check:

sudo systemctl list-units --type=service --state=running
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🛠️ Fix:

sudo systemctl disable --now avahi-daemonsudo systemctl disable --now cups
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2. SSH Is Too Open

On Ubuntu, SSH is often enabled — even if you didn’t configure it.

🔍 Check:

sudo systemctl status ssh
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🛠️ Fix:

# Only allow your IPsudo ufw allow from <your_ip> to any port 22
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# Disable root login and password authsudo nano /etc/ssh/sshd_config# Set:PermitRootLogin no  PasswordAuthentication no
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👉 Read Full Blog on Medium Here

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