Closing Security Vulnerabilities in Network Infrastructure: Step-by-Step Guide

Introduction

In today's world, cybersecurity has become one of the top priorities for businesses. Particularly, the security of network infrastructure is crucial to prevent attackers from infiltrating your systems. In this article, we will follow a step-by-step approach to closing security vulnerabilities, focusing on Firewall, DDoS protection, and WAF (Web Application Firewall) installations.

Source of Vulnerability

Many security vulnerabilities stem from misconfigured servers or inadequate security measures. For example, insufficient firewall settings on a VDS server can leave you vulnerable to DDoS attacks. Below, you will find the necessary steps to close such vulnerabilities.

Step 1: Firewall Installation

First, we need to create a basic set of firewall rules using iptables. Connect to your server via SSH and execute the following commands:

sudo iptables -A INPUT -m conntrack --ctstate ESTABLISHED,RELATED -j ACCEPT
sudo iptables -A INPUT -p tcp --dport 22 -j ACCEPT
sudo iptables -A INPUT -p tcp --dport 80 -j ACCEPT
sudo iptables -A INPUT -p tcp --dport 443 -j ACCEPT
sudo iptables -A INPUT -j DROP

These rules allow only specific connections while blocking all others.

Step 2: DDoS Protection

To protect against DDoS attacks, we can use fail2ban. First, install fail2ban:

sudo apt-get install fail2ban

Then, edit the configuration file:

sudo nano /etc/fail2ban/jail.local

Add the following lines to the content:

[sshd]
enabled = true
port = 22
filter = sshd
logpath = /var/log/auth.log
maxretry = 5
bantime = 600

Save the changes and restart the fail2ban service:

sudo systemctl restart fail2ban

Step 3: WAF Installation

Finally, you can protect your web applications by installing a Web Application Firewall (WAF). ModSecurity is one of the most popular WAF tools. First, install mod_security:

sudo apt-get install libapache2-mod-security2

Once the installation is complete, edit the modsecurity.conf file:

sudo nano /etc/modsecurity/modsecurity.conf

Find the following line and change it to On:

SecRuleEngine On

Save the changes and restart the Apache server:

sudo systemctl restart apache2

Conclusion

In this article, you learned the necessary steps to enhance the security of your network infrastructure. By implementing Firewall, DDoS protection, and WAF installation, you can make your servers more secure. Remember, cybersecurity is an ongoing process, and do not neglect to perform regular updates.