Closing Security Vulnerabilities in Network Infrastructure: Firewall, DDoS, and WAF I...

Security Vulnerabilities in Network Infrastructure and Solutions

In today's world, cybersecurity is one of the most critical aspects of server management. Especially security vulnerabilities in network infrastructure pose significant threats to the security of servers and data centers. In this article, we will explore how to close these vulnerabilities step by step through DDoS attacks, firewall settings, and Web Application Firewall (WAF) installations.

DDoS Attacks and Protection Methods

DDoS (Distributed Denial of Service) attacks overload a service, causing it to stop functioning. To prevent this, you can follow these steps:

• Step 1: Contract with a service that provides DDoS protection for your server. Services like Cloudflare or Akamai offer protection against such attacks.
• Step 2: Update your firewall settings. You can block specific IP addresses using the following command:

iptables -A INPUT -s [BAD_IP] -j DROP

• Step 3: Connect to your server via SSH and configure DDoS protection settings. For example, you can use fail2ban to block IPs that send too many requests within a specific time:

echo '[sshd]' >> /etc/fail2ban/jail.local
echo 'enabled = true' >> /etc/fail2ban/jail.local
echo 'filter = sshd' >> /etc/fail2ban/jail.local
echo 'action = iptables[name=sshd, port=ssh, protocol=tcp]' >> /etc/fail2ban/jail.local
echo 'logpath = /var/log/auth.log' >> /etc/fail2ban/jail.local
echo 'maxretry = 3' >> /etc/fail2ban/jail.local

Enhancing Security with Firewall Settings

A firewall controls network traffic and prevents unauthorized access. Therefore, a strong firewall configuration is crucial. You can optimize your firewall settings by following these steps:

• Step 1: Create basic rules using iptables or UFW (Uncomplicated Firewall) on your server. For example, to allow traffic only from specific IP addresses:

iptables -A INPUT -s [ALLOWED_IP] -j ACCEPT
iptables -A INPUT -j DROP

• Step 2: Control access to specific ports. You need to open ports 80 and 443 for your web server:

iptables -A INPUT -p tcp --dport 80 -j ACCEPT
iptables -A INPUT -p tcp --dport 443 -j ACCEPT

Web Application Firewall (WAF) Installation

A WAF protects web applications and is effective against attacks like SQL injection and XSS. When setting up a WAF, follow these steps:

• Step 1: Choose your WAF solution. You may prefer using an open-source WAF like ModSecurity.
• Step 2: To install ModSecurity, use the following commands:

apt-get install libapache2-mod-security2
a2enmod security2

• Step 3: Edit the ModSecurity configuration file. Open /etc/modsecurity/modsecurity.conf and change the following line to On:

SecRuleEngine On

• Step 4: Enable application rules. You can download and configure the OWASP ModSecurity Core Rule Set (CRS):

git clone https://github.com/coreruleset/coreruleset.git /usr/local/modsecurity-crs
mv /usr/local/modsecurity-crs/crs-setup.conf.example /usr/local/modsecurity-crs/crs-setup.conf

Conclusion

By following these steps, you can close security vulnerabilities in network infrastructure, protect your servers from DDoS attacks, and secure your web applications. Remember, continuously updating and configuring your security measures should be your goal.