Cloud Server Security Best Practices

Why Cloud Server Security is Important

Cloud servers store important business data and user information. Once attacked, it can lead to data breaches, service interruptions, and significant losses. Implementing security best practices is key to protecting cloud servers.

Account Security

1. Strong Password Policy

Password Requirements:

• Minimum 12 characters
• Include uppercase, lowercase, numbers, special characters
• Avoid personal information

2. Disable Root Remote Login

# Create new user
adduser newuser
usermod -aG sudo newuser

# Disable root SSH login
sudo vim /etc/ssh/sshd_config
# Modify: PermitRootLogin no
sudo systemctl restart sshd

3. Use SSH Key Authentication

# Generate SSH key pair
ssh-keygen -t rsa -b 4096
# Copy public key to server
ssh-copy-id username@server-ip

Network Security

1. Configure Firewall

Using UFW (Ubuntu):

sudo apt-get install ufw
sudo ufw default deny incoming
sudo ufw default allow outgoing
sudo ufw allow 22/tcp
sudo ufw allow 80/tcp
sudo ufw allow 443/tcp
sudo ufw enable

2. Configure Security Groups

Cloud service provider security group rules:

Rule	Protocol	Port	Source	Description
Inbound	TCP	22	Your IP	SSH access
Inbound	TCP	80	0.0.0.0/0	HTTP
Inbound	TCP	443	0.0.0.0/0	HTTPS
Outbound	ALL	ALL	0.0.0.0/0	All

System Security

1. Update System Regularly

# Ubuntu/Debian
sudo apt-get update
sudo apt-get upgrade

2. Install fail2ban

sudo apt-get install fail2ban
sudo systemctl start fail2ban
sudo systemctl enable fail2ban

Application Security

1. Use HTTPS

Install Let’s Encrypt certificate:

sudo apt-get install certbot python3-certbot-nginx
sudo certbot --nginx -d yourdomain.com

2. Configure Nginx Security Headers

add_header X-Frame-Options "SAMEORIGIN";
add_header X-Content-Type-Options "nosniff";
add_header X-XSS-Protection "1; mode=block";
add_header Strict-Transport-Security "max-age=31536000; includeSubDomains";

Data Backup

1. Regular Backup Strategy

Backup types:

• Full backup: Weekly
• Incremental backup: Daily
• Log backup: Real-time

2. Use Cloud Backup Services

Alibaba Cloud snapshots:

aliyun ecs CreateSnapshot --InstanceId i-xxxxx

Monitoring and Auditing

1. Log Monitoring

# View SSH login logs
sudo tail -f /var/log/auth.log

2. Set Up Alerts

Configure alert rules for:

• CPU usage > 80%
• Memory usage > 90%
• Disk usage > 85%
• Abnormal login attempts

Summary

Cloud server security is an ongoing process requiring:

1. Regular checks - Regularly check system security status
2. Timely updates - Update system and software promptly
3. Backup important data - Ensure data recoverability
4. Monitor anomalies - Monitor abnormal system behavior
5. Prepare response plans - Prepare emergency response procedures

Remember: Security has no destination, only continuous improvement.

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• Cloud Server Performance Optimization
• Cloud Server Selection Guide