KNOWLEDGE

Web Application Firewall: First Defense Against Cyber Threats

Posted on by iconext writer
Web Application Firewall
23
Jun

In today’s digital world, web applications have become essential to both business operations and our daily lives. With this growing reliance comes an urgent need to protect sensitive data and ensure application security. Cyberattacks like SQL Injection, Cross-Site Scripting (XSS), and Distributed Denial-of-Service (DDoS) are becoming more frequent and increasingly sophisticated.

That’s where Web Application Firewalls (WAFs) come in. These powerful tools are designed to monitor and protect the flow of data between users and web applications, helping to block malicious traffic before it causes harm.

In this article, we’ll explore what WAFs are, how they work, the different types available, and the range of threats they defend against—giving you the insights you need to choose the right WAF solution for your organization.

The Origins of WAF

The concept behind the Web Application Firewall (WAF) stems from the need to protect web applications from threats that specifically target the application layer. These are vulnerabilities that traditional firewalls are not equipped to handle. As more businesses use the internet and web applications, cyberattacks like SQL Injection, Cross-Site Scripting (XSS), and DDoS have also increased. Stopping these attacks requires special tools to detect and block them.

Traditional firewalls were originally designed to filter traffic at the network layer. However, as cyber threats became more sophisticated, WAFs were developed to provide protection at the application layer (Layer 7) of the OSI (Open Systems Interconnection) model*1, offering a more targeted defense against complex attacks.

*1 The OSI 7 Layers Model is a framework that explains how data is transmitted between two devices. It breaks the communication process into seven layers, with each layer handling a specific function to ensure that information is sent and received accurately.

Differences Between WAF and Traditional Firewalls

Level of Protection

  • Traditional Firewall: Operates at the network layer to filter data packets between networks. It focuses on blocking network-level attacks such as IP spoofing or port scanning.
  • WAF: Works at the application layer, specifically protecting web applications from more complex threats like SQL Injection and Cross-Site Scripting (XSS).

Operation

  • Traditional Firewall: Inspects data packets based on predefined rules, such as allowing or denying traffic based on IP addresses and port numbers.
  • WAF: Analyzes the content of HTTP/HTTPS traffic to detect harmful behavior and prevent malicious data from reaching the web server.

How WAF Works

A Web Application Firewall (WAF) automatically filters incoming HTTP/HTTPS requests from users based on predefined policies or rules. This enables it to block attacks quickly and efficiently. For example, in the case of a DDoS attack, WAFs can instantly limit the number of requests without affecting the normal operation of the website.

Image of Web Application Firewall
Image of Web Application Firewall

Types of WAF Deployment

WAFs come in three main types:

  • Network-based WAF: Deployed via hardware appliances, typically offering high performance but at a higher cost.
  • Host-based WAF: Installed directly on the application server. It is more affordable but consumes more server resources.
  • Cloud-based WAF: Cost-effective and easy to deploy, making it ideal for organizations that prefer not to manage hardware infrastructure.

What Can a WAF Protect Against?

A Web Application Firewall (WAF) can defend against a wide range of attacks, including:

  • Injection: Blocks threats like SQL Injection and other code injection attacks.
  • Broken Authentication and Session Management: Prevents unauthorized access to user sessions and sensitive session data.
  • Cross-Site Scripting (XSS): Protects against malicious scripts that can steal user data.
  • Security Misconfiguration: Mitigates risks caused by improper security settings that may expose application vulnerabilities.
  • Sensitive Data Exposure: Helps prevent the leakage of critical information, such as credit card numbers or personal data.

Popular WAF Services Available Today

WAF solutions are now available in various forms, including cloud-based services and on-premise deployments. Several major providers offer widely used WAF products. Here are some of the most popular:

AWS WAF

  • Provided by Amazon Web Services
  • Protects web applications hosted on Amazon Cloud, such as API Gateway, CloudFront, and Application Load Balancer (ALB)

Azure Web Application Firewall

  • Offered by Microsoft Azure
  • Works with Azure Front Door and Application Gateway to secure web traffic

Cloudflare WAF

  • Protects against OWASP Top 10 vulnerabilities, DDoS attacks, and malicious bots
  • Easy to use, with no need for server-side installation

Conclusion

A Web Application Firewall (WAF) is an essential tool for protecting web applications against threats that traditional firewalls cannot fully address. By operating at the application layer, WAFs provide a crucial layer of defense that helps ensure data security and system stability.

With advancements in cloud technology, Cloud-based WAFs also simplify deployment and management, offering greater flexibility and enhanced security for businesses. Choosing the right WAF solution is therefore a key factor in strengthening the security posture of an organization’s web applications—especially in today’s threat-filled digital landscape.

Source: Cloudflare

Image by Freepik

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