What is a WAF?

A WAF (Web Application Firewall) is a security solution designed to protect web applications from a wide range of cyber threats. It acts as a protective shield between your website and incoming traffic from the internet, helping to block attacks such as SQL Injection, Cross-Site Scripting (XSS), and DDoS that target web applications.

Unlike traditional firewalls that safeguard overall network infrastructure, a WAF focuses specifically on analyzing and filtering HTTP/HTTPS traffic to detect and block suspicious behavior before it can harm the system.

The Role of WAF in Website Security

WAF plays a critical role in maintaining website security through the following functions:

1. Preventing Cyberattacks: A WAF protects websites against common attacks such as SQL Injection, XSS, and other application vulnerabilities.

2. Protecting Sensitive Data: It helps prevent unauthorized access to user data, including passwords and payment information.

3. Enhancing Performance: Some advanced WAFs include traffic optimization features that reduce server load and improve website speed.

4. Ensuring Compliance: WAF supports businesses in complying with standards such as PCI DSS (Payment Card Industry Data Security Standard).

5. Monitoring and Analysis: The system provides detailed traffic reports and threat analysis to help administrators adjust security strategies in real time.

How Does a WAF Work?

WAFs operate based on a predefined ruleset or security policy. The basic process includes:

1. Traffic Inspection: The WAF examines all incoming HTTP/HTTPS requests to your website.

2. Rule Matching: It compares the traffic against known attack signatures (signature-based detection) or detects anomalies based on behavior (anomaly-based detection).

3. Block or Allow: If a threat is detected, the WAF blocks the request instantly. Otherwise, legitimate requests are forwarded to the web server.

Types of Attacks a WAF Can Prevent

WAFs are equipped with a variety of security mechanisms and advanced features, such as:

• Vulnerability Protection: Blocks exploitation of known or unpatched vulnerabilities in web applications.

• Geo-based Access Control: Restricts or blocks access from high-risk regions or countries.

• Sensitive Data Leakage Prevention: Detects and prevents leakage of critical data like credit card numbers or personal information.

• Webpage Tamper Protection: Monitors web content for unauthorized changes or injection attacks.

Thanks to these capabilities, a WAF can effectively defend against:

• SQL Injection: Inserting malicious SQL code to access database content.

• Cross-Site Scripting (XSS): Injecting JavaScript to steal user data or hijack sessions.

• Layer 7 DDoS Attacks: Overloading the website with fake requests to cause downtime.

• File Inclusion: Exploiting file inclusion vulnerabilities to access sensitive system files.

Who Should Use a WAF Solution?

A Web Application Firewall (WAF) is an essential cybersecurity tool for any website or web app that handles a significant amount of user interaction or sensitive data. With the ability to detect and block common attacks like SQL Injection, XSS, DDoS, etc., a WAF helps protect data, maintain system performance, and ensure a smooth user experience.

EVG Cloud’s WAF stands out with its flexibility in deployment (cloud-based or on-premise), customizable security rules, real-time traffic monitoring, and expert technical support. That makes it ideal for a wide range of industries and business types:

1. E-commerce

E-commerce websites store sensitive data such as login credentials, shipping addresses, purchase history, and especially payment information (credit cards, e-wallets). A successful attack could result in data breaches, reputational damage, and financial loss.

Ideal users:

• Online retail websites

• Small and medium-sized e-commerce platforms

• Businesses using Shopify, Haravan, WooCommerce, etc.

2. Finance – Banking – Insurance

Financial systems manage massive volumes of personal data, bank accounts, transactions, and digital contracts. These systems must not only be secure but also compliant with regulations like PCI DSS and ISO 27001.

Ideal users:

• Fintech startups

• Online payment gateways

• Digital banks / e-wallets

• Online insurance companies

• Securities and investment firms

3. Legal Services – Public Administration

Legal offices and government portals often store contracts, legal documents, and personal records. If compromised, this data can have serious legal and reputational consequences.

Ideal users:

• Law firms and notary offices

• Legal consulting platforms

• Public portals for document submission and legal reference

4. Education – E-learning

Online learning platforms store student data, course content, exam results, and often support online tuition payments. These platforms attract high traffic, making them vulnerable to DDoS or web-based attacks.

Ideal users:

• Learning Management Systems (LMS)

• Online training and e-learning platforms

• Student information and school management portals

5. Healthcare

Medical websites store patient records, prescriptions, and other sensitive data that require the highest level of protection against data leaks or unauthorized access.

Ideal users:

• Hospitals and clinics with online booking systems

• Health platforms and telemedicine applications

6. Media – Digital Content

High-traffic websites and blogs are prime targets for attackers looking to inject malware, display unauthorized ads, or cause service disruptions. Additionally, user data, articles, and comment systems must be secured.

Ideal users:

• Online news websites

• Popular blogs

• Review websites and forums

• Video and content-sharing platforms

7. SaaS Providers

SaaS platforms operate primarily through web browsers and often store user data in the cloud. Protecting API endpoints and customer data is critical for maintaining platform security.

Ideal users:

• Online software solutions

• CRM, HRM applications, and other web-based tools

8. Travel – Hospitality – Online Booking

Websites in this industry handle room/ticket bookings and online payments. Besides customer data, they process credit card information and payment confirmations that must be protected.

Ideal users:

• Hotel booking websites

• Tour and airline ticket platforms

• Online booking systems for restaurants, spas, etc.

Conclusion

A Web Application Firewall (WAF) is an indispensable solution for protecting websites against a wide range of internet threats. With its ability to analyze traffic and block malicious activity, a WAF—especially from EVG Cloud—is the ideal choice for any organization looking to enhance website security.

No matter your industry, deploying a WAF helps reduce the risk of cyberattacks, secure sensitive data, and preserve your brand reputation.

Looking to secure your website? Contact our expert team via hotline (+84) 968206168 to get personalized advice and discover the best WAF solution for your needs.