NAXSI vs Qualys Web Application Firewall
NAXSI and Qualys Web Application Firewall take different approaches to web application security. Consider your team's expertise and infrastructure preferences when evaluating these options.
NAXSI and Qualys Web Application Firewall take fundamentally different approaches to web application security. Understanding your infrastructure and team capabilities will help determine which approach fits your needs.
Overview
NAXSI and Qualys Web Application Firewall are both popular web application firewall solutions. This comparison will help you understand the key differences and choose the right one for your needs.
A lightweight, open source WAF module for NGINX that uses a scoring-based approach instead of signature matching, blocking attacks by detecting suspicious patterns rather than maintaining a vulnerability database.
Cloud-managed WAF from Qualys that integrates with their vulnerability scanning platform, enabling one-click virtual patching of discovered vulnerabilities. Note — product was decommissioned September 2024.
Quick Comparison
| Feature | NAXSI | Qualys Web Application Firewall |
|---|---|---|
| Overall Rating | 3.4/5 | 3.0/5 |
| Free Tier | Yes | No |
| Pricing Model | Free (Open Source, GPLv3) | Subscription, per-asset licensing (product decommissioned) |
| Ease of Use | 2.8/5 | 3.2/5 |
| Value for Money | 4.5/5 | 2.5/5 |
| Support | 2.5/5 | 3.5/5 |
| Open Source | Yes | No |
| Platforms | NGINX, Linux (Debian, Ubuntu, CentOS), FreeBSD, OpenBSD, NetBSD, Docker | VMware, Hyper-V, Docker, AWS, Azure, Google Cloud Platform |
| Compliance | N/A (supports OWASP Top 10 protection patterns) | PCI DSS, SOC 2, FedRAMP, ISO 27001 (Qualys platform level) |
Pricing Comparison
Qualys Web Application Firewall
Model: Subscription, per-asset licensing (product decommissioned)
Qualys WAF (Decommissioned)
Previously subscription-based
Features Comparison
NAXSI
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Scoring-Based Detection
Assigns scores to suspicious patterns in requests. Blocks when the cumulative score exceeds a threshold, rather than relying on exact signature matches.
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Learning Mode
Monitors traffic and automatically generates whitelist rules for legitimate application behavior, reducing manual tuning effort during initial deployment.
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Virtual Patching
Apply custom rules to block specific vulnerabilities without modifying application code. Rules target raw requests or specific fields like headers, args, and body.
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Deny-by-Default
Operates like a DROP firewall. Common attack characters and patterns are blocked unless explicitly whitelisted for the target application.
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Lightweight Footprint
Written in C with only libpcre as a dependency. Adds minimal overhead to NGINX request processing.
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Dynamic Module Support
Can be compiled as a dynamic NGINX module, allowing it to be loaded without recompiling NGINX from source.
Qualys Web Application Firewall
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WAS Integration
Automatically generate WAF rules from Qualys Web Application Scanning results for one-click virtual patching.
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Cloud-Managed Appliance
Virtual appliance deployed locally but managed centrally through the Qualys Cloud Platform.
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Custom Security Policies
Flexible policy engine with reusable rules and templates for common platforms and custom applications.
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Pre-Built CMS Policies
Out-of-the-box protection policies for WordPress, Joomla, Drupal, SharePoint, and Outlook Web Application.
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Security Event Analytics
Detailed dashboards with traffic summaries, threat trends, and drill-down capabilities for incident investigation.
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Local Traffic Processing
Application traffic stays within your environment for minimal latency and full data control.
Which One Is Right for You?
The best WAF depends on your specific requirements, infrastructure, and team expertise.
NAXSI
- You need: Teams already running NGINX who want lightweight inline WAF protection, budget-conscious deployments, applications with predictable request patterns, virtual patching use cases
- You want to start with a free tier
- You prefer open-source solutions
- You're using: NGINX, Linux (Debian, Ubuntu, CentOS), FreeBSD, OpenBSD, NetBSD, Docker
Qualys Web Application Firewall
- You need: Historical reference; previously suited for Qualys platform customers wanting integrated vulnerability management and WAF
- You're using: VMware, Hyper-V, Docker, AWS, Azure, Google Cloud Platform
We recommend evaluating both options with a trial or free tier before committing. Consider your existing infrastructure, team expertise, compliance requirements, and budget.
Frequently Asked Questions
Which is better for startups: NAXSI or Qualys Web Application Firewall?
NAXSI offers a free tier while Qualys Web Application Firewall does not, which may be important for early-stage startups. Qualys Web Application Firewall scores higher for ease of use (3.2/5), which is valuable for smaller teams. Consider your immediate security needs and growth plans when choosing.
Which has better support: NAXSI or Qualys Web Application Firewall?
Qualys Web Application Firewall has a higher support rating (3.5/5) compared to NAXSI (2.5/5). However, support quality can vary based on your plan tier - enterprise customers typically receive more responsive support from both providers. Consider evaluating support during a trial period.
Which is easier to implement: NAXSI or Qualys Web Application Firewall?
Qualys Web Application Firewall scores higher for ease of use (3.2/5) versus NAXSI (2.8/5). The actual implementation effort depends on your existing infrastructure and team expertise.
Which is more cost-effective: NAXSI or Qualys Web Application Firewall?
NAXSI offers a free tier while Qualys Web Application Firewall requires a paid plan. NAXSI scores higher for value (4.5/5). Total cost depends on your traffic volume, required features, and support level needs.
Which works better with AWS: NAXSI or Qualys Web Application Firewall?
Qualys Web Application Firewall explicitly supports AWS while NAXSI's AWS integration may vary. Consider whether native AWS integration or cross-cloud portability matters more for your use case.