What is a Web Application Firewall (WAF)?

A Web Application Firewall (WAF) is a specialized security layer designed to protect web applications against common attack vectors such as SQL Injection, Cross-Site Scripting (XSS), and File Inclusion. Operating at the application layer (Layer 7 of the OSI model), a WAF inspects incoming HTTP/HTTPS traffic to detect and block malicious behavior before it reaches the application server.

How WAFs Work

WAFs function as an intelligent filter positioned between users and the web application server. Every request from a user is analyzed by the WAF to identify malware, dangerous commands, or suspicious behavior patterns before being forwarded to the backend.

There are two primary operational models:

• Whitelist-based WAFs: Only allow predefined, trusted traffic patterns.

• Blacklist-based WAFs: Block traffic matching known attack signatures.

Modern WAFs often leverage machine learning algorithms to identify zero-day threats and behavioral anomalies that traditional signatures might miss.

Types of WAFs

• Hardware-based WAFs: Deployed on-premises, ideal for large enterprises requiring maximum control and low-latency performance.

• Software-based WAFs: Installed on dedicated servers or virtual machines.

• Cloud-based WAFs: Offered as a managed service by cloud providers, ideal for scalability and ease of deployment.

Real-World Applications of WAF

• Protecting e-commerce websites from fraud and abuse.

• Securing mobile application APIs against injection and logic-based attacks.

• Enhancing security for SaaS platforms.

• Ensuring compliance with standards such as PCI-DSS or ISO 27001.

What is a Web Proxy?

A Web Proxy acts as an intermediary server between the user and the destination server, offering functions such as IP masking, access control, and content caching. Operating at the network and transport layers, it does not analyze the application-level content like a WAF.

How Proxies Work

When a user sends a request, the proxy intercepts and forwards it on behalf of the user to the destination server. The server's response is also relayed through the proxy back to the client. This mechanism enables:

• Hiding the user's IP address from the destination server.

• Content filtering or blocking of websites.

• Caching of static content to improve load speeds and reduce bandwidth consumption.

Types of Web Proxies

• Forward Proxy: Represents users in accessing the internet. Commonly used to enforce corporate internet policies or filter internal network traffic.

• Reverse Proxy: Represents backend servers, handling incoming traffic from external sources. Often used for load balancing, TLS termination, and enhanced security.

Real-World Applications of Web Proxy

• Enabling anonymous browsing for users.

• Allowing organizations to control and monitor employee internet access.

• Hiding real IP addresses of backend servers behind a reverse proxy.

• Acting as a component in CDN and traffic distribution architectures.

Comparison Table: WAF vs Web Proxy

Combining WAF and Web Proxy: A Holistic Security Architecture

In today’s increasingly complex cybersecurity landscape, relying on a single security layer is insufficient. Both Web Application Firewalls and Web Proxies serve distinct roles in a comprehensive security strategy. Rather than choosing between them, modern organizations often deploy both to establish a multi-layered defense architecture:

• WAFs are responsible for deep inspection of incoming requests, blocking logic-based and injection attacks before they reach the application.

• Web Proxies act as the gateway for incoming and outgoing network traffic, enabling control over access, content filtering, and traffic routing to backend infrastructure.

Depending on security priorities, infrastructure design, and budget, businesses can select the most appropriate solution or combine WAF and proxy technologies to achieve enhanced protection, performance optimization, and access control simultaneously.

EVG Cloud’s WAF Solution – Tailored Web Security for Vietnamese Enterprises

EVG Cloud offers a specialized Web Application Firewall solution engineered for the unique requirements of Vietnamese enterprises, taking into account local application structures, common software platforms, and user behavior.

Key Advantages of EVG Cloud’s WAF:

• Tailored for Vietnamese Web Platforms: Deep understanding of locally developed websites, Vietnamese-language CMSs, and internal CRMs.

• Real-Time Threat Prevention: Comprehensive protection against SQLi, XSS, RFI, LFI, CSRF, and advanced logic-based attacks.

• Fully Localized Interface: Vietnamese language support, intuitive alerts, and easy-to-use dashboards—enabling effective security management even without an in-house cybersecurity team.

• Easy Integration: Seamless compatibility with both domestic and international hosting and cloud platforms.

• Cost-Effective: Competitive pricing compared to global WAF vendors, while maintaining high standards of protection, performance, and reliability.

This solution is ideally suited for organizations managing e-commerce websites, media portals, mobile APIs, fintech platforms, and internal enterprise systems that need to meet security standards such as PCI-DSS and ISO 27001.

Thanks to its outstanding adaptability and performance, EVG Cloud’s WAF is the ideal choice for businesses seeking a secure, scalable, and cost-optimized application protection framework built for the Vietnamese market.

Contact our cybersecurity experts today via hotline (+84) 968206168 to design a WAF solution that fits your needs and strengthens your application infrastructure—efficiently and affordably.