11:43
31/05/2025
Introduction to Web Application Firewall (WAF)
What is a WAF?
In today’s era of rapid digital transformation, most enterprises have deployed web applications to facilitate operations for customers, partners, and internal users. However, these applications have consequently become prime targets for cyberattacks. A Web Application Firewall (WAF) emerges as the first line of defense, shielding applications from external threats.
A WAF is a specialized security system that analyzes and filters incoming HTTP/HTTPS traffic from users or external servers. It aims to detect and block malicious behaviors such as SQL Injection, Cross-Site Scripting (XSS), File Inclusion, and application-layer Distributed Denial-of-Service (DDoS) attacks.
Role in Web Security
Beyond functioning as a protective tool, the WAF is a core component in modern Zero Trust security strategies. It helps to:
Safeguard sensitive data, including personal information and banking credentials.
Detect and prevent advanced persistent threats (APT).
Ensure the availability and reliability of web services.
Comply with security standards such as PCI-DSS, GDPR, and ISO 27001.
Modern WAFs are not limited to filtering web content—they also determine who is allowed to access resources, how often, and from where. The following three access control mechanisms form the foundation of robust WAF protection:
Rate Limiting: Caps the number of requests within a specific timeframe to thwart DDoS attacks or bot-driven request floods.
IP Whitelisting: Grants access only to pre-approved IP addresses, often used for internal APIs or administrative access.
Mechanism: Limits the number of requests from a single IP address over a defined period. Excessive requests trigger temporary blocks.
Use Cases:
Login pages
Internal APIs
Search engines or shopping carts
Advantages:
Protects against brute-force and application-layer DDoS attacks
Enhances resource efficiency and system performance
Limitations: Overly strict thresholds may disrupt legitimate user experiences
Mechanism: Permits access solely from trusted IP addresses.
Use Cases:
Admin panel access
API communications between isolated systems
Advantages:
High security in restricted zones
Easy control in environments with static IPs
Limitations: Inconvenient for remote employees or users with dynamic IPs
Mechanism: Determines access based on IP geolocation and applies predefined rules (allow, restrict, or block).
Use Cases:
Domestic-only service providers
Blocking regions with high volumes of cybercrime
Advantages:
Prevents attacks from high-risk geographies
Assists in complying with data localization laws
Limitations:
Easily bypassed with VPNs
Inappropriate for globally distributed user bases
Geo-blocking acts as the first layer by immediately denying requests from high-risk zones.
IP Whitelisting adds another filter for sensitive components like internal APIs and admin interfaces.
Rate Limiting monitors legitimate sources for abnormal behavior, stopping excessive traffic or bots.
Rather than relying on a single layer of protection, combining these techniques replicates a multi-tiered security architecture. If one layer is breached, others remain to ensure resilience.
Early filtering of malicious requests reduces backend load, enhancing the speed of legitimate user interactions. It also reduces downtime by neutralizing threats at the network edge.
Security regulations (GDPR, PCI-DSS, ISO 27001) often mandate fine-grained access control by IP, region, and frequency. Integrating all three techniques supports easier compliance during audits.
EVG Cloud’s WAF identifies and mitigates threats from the OWASP Top 10—including SQL Injection, XSS, CSRF, SSRF—through automated threat pattern updates to remain effective against evolving exploits.
Beyond static rule sets, EVG Cloud applies AI/ML to:
Monitor real-time traffic behavior
Learn valid user patterns
Identify disguised malicious behavior
Auto-suggest optimal security policies
This intelligent detection minimizes false positives and maximizes threat detection accuracy.
The admin interface supports both Vietnamese and English, enabling both technical and non-technical teams to easily configure key functions like rate limiting, IP whitelisting, and geo-blocking with just a few clicks.
EVG Cloud provides around-the-clock assistance from domestic security professionals. The team offers hands-on help in audits, incident response, and tailored configuration—giving EVG a significant edge over global providers.
As cyber threats grow in sophistication, businesses must embrace proactive, layered, and adaptive defenses. The combined application of rate limiting, IP whitelisting, and geo-blocking forms a robust foundation for web application security.
However, isolated deployment of these features is insufficient. An integrated WAF platform like EVG Cloud—backed by automation, AI, a user-centric interface, and expert support—delivers a comprehensive solution. It enables rapid adaptation to shifting threat landscapes and ensures sustainable web security in the digital era.
11:43
31/05/2025
11:43
31/05/2025
11:43
31/05/2025