Lesson 4.73: The first ten minutes on a new server
A new server is never more exposed than in its first hours: default settings, services nobody asked for, updates not yet configured. Attackers scan the whole internet continuously and find new machines within minutes. In the lab you take a freshly delivered server through the first checks: turn on automatic security updates, list what's listening on the network, find a service from the old days that sends passwords in clear text, and switch it off for good.
15 min
You will learn to
- Explain why new systems are scanned within minutes
- Turn on automatic security updates (unattended-upgrades)
- List listening network ports
- Recognise an unencrypted legacy service
- Disable a service now and at boot
Key terms
- Hardening
- Reducing a system's attack surface: removing what isn't needed and setting safe defaults.
- Unattended upgrades
- Ubuntu/Debian mechanism that installs security updates automatically.
- Listening port
- A network port where a program waits for connections.
- Telnet
- An old remote login protocol without encryption; replaced by SSH.
- Baseline
- A documented secure starting configuration every new system must reach.
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