OpenSSH Server hardening and security best practices

✅ Keep OpenSSH Up to Date

• Always keep your OpenSSH server software updated to the latest version. Security vulnerabilities are frequently discovered in SSH software, and keeping your version patched is critical.

✅ Configure SSH Idle Timeout

• Set an idle timeout for SSH sessions to automatically terminate sessions after a period of inactivity. This prevents sessions from being left open and vulnerable.

✅ Change Default Port

• Change the default SSH port from 22 to a non-standard port. This makes automated attacks against port 22 ineffective.

✅ Implement Two-Factor Authentication (2FA)

• Require users to use a second factor like a security key in addition to their password when logging in over SSH. This adds an additional layer of security.

✅ Disable SSH Root Logins

• Disable the ability to log in as root over SSH. Require users to log in with personal accounts and then use sudo to elevate privileges.

✅ Regularly Audit SSH Server Configuration

• Periodically review your SSH server settings to ensure they still meet your security policies. Settings can drift over time.

✅ Disable Unused SSH Features (i.e. SSHv1)

• Disable outdated and insecure SSH protocol versions like SSHv1 that are no longer considered secure.

✅ Monitor SSH Logs

• Review SSH logs regularly for signs of unauthorized access attempts or brute force attacks.

✅ Implement Firewall Rules