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SSH Server: Restrict Who Can Log In
MediumNetworking10-20 minThe brief
Lock down SSH access by editing /etc/ssh/sshd_config, per /root/case/assignment.env:
1. Allow only one account to log in — AllowUsers REQ_USER
2. Limit auth attempts per connection — MaxAuthTries REQ_TRIES
3. Disable X11 forwarding — X11Forwarding no
The allowed user and try limit vary per session. See /root/case/brief.txt.
What you'll do
- Restrict SSH logins to specific accounts with AllowUsers
- Lower the per-connection authentication attempt limit
- Disable X11 forwarding
- Apply least-privilege to a network service
Hands-on lab: you work on a real Linux box in your browser, graded on the machine's actual state.