How to Select a WAF for New Webmasters(Part 1)

Web Application Firewall (WAF)

A Web Application Firewall (WAF) is a security software installed on a web server by web administrators. It is used to filter, monitor, and block HTTP traffic that is passing through the web service. The WAF serves as a first line of defense against hacker attacks such as XSS (Cross-Site Scripting) and SQL injection, similar to how masks protect us during flu season. Since its inception in the 1990s, WAF technology has evolved, but the fundamental principles and protective measures have remained constant. Despite this, the market is flooded with a plethora of WAF products. Choosing a WAF that offers robust protection and ease of use is an essential skill for new webmasters. Today, we will discuss the essential components of a WAF product and how its various metrics impact overall protection. This article aims to be simple and easy to understand, wishing all webmasters great traffic and safe operations.

False Positive Rate: Importance 🌟🌟🌟🌟🌟

The false positive rate of a WAF is a crucial metric, directly affecting its usability and business continuity. Here are several aspects influenced by the false positive rate:

• Business Continuity: A high false positive rate might lead to legitimate business traffic being wrongly intercepted, impacting user experience and business operations.
• Security and Business Balance: The false positive rate needs to be balanced with business requirements. In some cases, to ensure security, a certain level of false positives might be acceptable, but an excessively high false positive rate diminishes the WAF’s effectiveness.
• Compliance: The false positive rate affects an organization’s ability to meet compliance requirements. Regulatory compliance is a major driver for modern enterprises in building network security capabilities. Using a WAF system helps organizations more easily meet regulatory requirements.
• Resource Optimization: Optimizing the false positive rate can improve the WAF’s resource utilization, reducing unnecessary consumption of computing resources, storage, and network bandwidth.
• Security Decisions: The false positive and false negative rates are key performance indicators of a WAF system, directly influencing its usability and reliability. To reduce false positive and false negative rates, a WAF system needs continuous updates and optimization of detection algorithms and feature libraries to enhance detection accuracy and efficiency.
• Logs and Reports: A WAF system should provide rich logging and reporting features so users can promptly understand and analyze the system's security status, making informed decisions. The accuracy and usability of these logs and reports are directly impacted by the false positive rate.
• User Experience: The false positive rate directly impacts the end-user experience. If the false positive rate is too high, users may encounter frequent service interruptions or access restrictions, lowering user satisfaction.
• Security Policy Adjustment: Analyzing the false positive rate helps the security team adjust and optimize security policies, reducing false positives while enhancing detection of real attacks.

To check a WAF’s false positive rate, since the test samples are not unique, the false positive rates provided by major WAF vendors might not fully apply to your environment. You can use BlazeHTTP to test it, but treat this tool as a reference, similar to a benchmark tool.

Queries Per Second (QPS): Importance 🌟🌟🌟

QPS, or Queries Per Second, directly reflects the performance and processing capability of a WAF. It is especially important for evaluating a WAF's performance in high-concurrency scenarios.

• Processing Capability: QPS indicates the maximum throughput capacity of a WAF, showing how many queries it can handle per second.
• System Load: QPS helps measure and express the current system load, providing insight into the system’s operational status.
• Business Impact: If a WAF’s QPS is lower than the business demand, it may cause service delays or packet loss, affecting user experience.
• Configuration and Optimization: Understanding a WAF’s QPS capability aids in the reasonable configuration of resources and performance optimization, ensuring the WAF can effectively handle expected traffic loads.
• Service Limits: In some cloud service providers, the QPS of a WAF may have limitations. Exceeding this limit might lead to additional costs or service degradation.
• Monitoring and Alerts: QPS is a crucial metric for WAF monitoring. By monitoring QPS, administrators can quickly identify and respond to potential performance issues or attack behaviors.

Many WAF products charge based on different QPS levels. How to achieve greater QPS processing with less money is a key point when choosing a WAF.

HTTP Flood DDoS Protection 🌟🌟🌟

HTTP Flood DDoS attacks simulate multiple users simultaneously accessing the target website, sending a large number of legitimate requests, consuming server resources, and causing the server to slow down or crash, achieving a Denial of Service (DoS) effect at the application layer (L7). Here are some key points of HTTP Flood DDoS protection:

• Data Caching Optimization: Store frequently accessed data in memory, reducing database queries and speeding up response times.
• Request Rate Control: Implement rate limiting on user requests and manage them based on session identifiers (SID).
• IP Access Restriction: Set rules at the firewall or load balancer level to limit the access frequency of abnormal IP addresses.
• CDN Traffic Distribution: Use CDN nodes to distribute traffic, effectively resisting concentrated attacks.
• Reverse Proxy Usage: A reverse proxy can hide the real IP address of the origin server and filter out some malicious requests, reducing the impact of HTTP Flood DDoS attacks on the server.
• Monitoring and Real-time Response: Monitor website traffic and server performance in real-time. When anomalies are detected, respond promptly to detect and mitigate HTTP Flood DDoS attacks early.

Open source WAF recommendation: SafeLine

SafeLine WAF is a free, open source and self-hosted WAF that protects your web applications from cyber attacks.

It's very easy to install, configure and operate. If you test, you'll get surprised by its low false positive rate, WAF performance and HTTP flood prevention capabilities.

Website:https://waf.chaitin.com/
Github:https://github.com/chaitin/SafeLine
Discord:https://discord.gg/dy3JT7dkmY