NGINX WAF Alternatives: App Protect vs. ModSecurity vs. SafeLine WAF

Web application firewalls (WAFs) are crucial for protecting web services against attacks such as SQL injection, XSS, and DDoS.

While NGINX does not include a built-in WAF, it supports several external WAF modules and proxies that can be used to harden security.

In this article, we compare three of the most popular WAF options for NGINX users: F5 NGINX App Protect, ModSecurity, and SafeLine WAF.

1. F5 NGINX App Protect

NGINX App Protect is a commercial WAF developed by F5 Networks. It is designed to work natively with NGINX Plus.

Pros

• Tightly Integrated with NGINX Plus: Offers seamless integration with commercial NGINX deployments.
• Enterprise-Grade Features: Includes behavioral DoS protection, bot mitigation, and threat intelligence feeds.
• Declarative Configuration: Uses JSON-based policies, making it CI/CD friendly.

Cons

• Commercial Only: Requires a license for NGINX Plus and App Protect.
• Complex Setup: Initial configuration can be steep for new users.

2. ModSecurity (OWASP CRS)

ModSecurity is a widely used open-source WAF that can be integrated with NGINX via connectors.

Pros

• Free & Open Source: No licensing costs.
• Community Supported: Backed by OWASP with access to the OWASP Core Rule Set (CRS).
• Highly Configurable: Supports custom rules and plugins.

Cons

• Performance Impact: May introduce latency under high load.
• Complex Rule Management: Rule tuning is time-consuming and can cause false positives.
• Limited Modern Features: Lacks advanced bot detection or behavioral analysis.

3. SafeLine WAF

SafeLine (https://ly.safepoint.cloud/ShZAy9x) is a modern, self-hosted WAF that supports reverse proxy and high-performance rule matching. It’s especially popular among startups, homelabs, and self-hosted enthusiasts.

Pros

• Lightweight & Fast: Written in Rust with high performance even on low-resource servers.
• Easy to Deploy: Offers Docker-based deployment and a web GUI.
• Rich Feature Set: Includes rate limiting, GeoIP blocking, custom rules, and real-time traffic insights.
• Free Community Edition: Ideal for developers and small teams.
• Self-Hosted & Transparent: All traffic stays on your infrastructure.

Cons

• Newer Project: Smaller ecosystem compared to ModSecurity.
• No Native NGINX Module: Works as a reverse proxy, not an embedded module.

Comparison Table

Conclusion

Choosing the right WAF depends on your organization’s size, needs, and technical preferences:

• Choose App Protect if you are already using NGINX Plus and need a tightly integrated enterprise-grade solution.
• Choose ModSecurity if you value open-source flexibility and are comfortable managing complex rule sets.
• Choose SafeLine WAF if you want an easy-to-deploy, high-performance, self-hosted WAF with modern features.

Each of these tools has strengths, and the best fit will depend on your specific use case and team capabilities.