WAF as a Service

WAF as a Service (WAFaaS) is a cloud-delivered web application firewall that protects web applications and APIs from common and advanced threats, without requiring customers to deploy or manage on-premises hardware or virtual appliances. It is consumed as a managed service, typically delivered at the edge or through a cloud platform, and is designed to scale automatically with application traffic.

How WAFaaS works

WAFaaS operates by placing a security control layer between users and applications:

1. Traffic is routed through the WAF
   Incoming requests are directed through the WAF via DNS changes, reverse proxying, edge network integration, or lightweight agents/connectors (depending on the provider).

2. Requests are inspected in real time
   The service analyzes HTTP/S and API traffic for malicious patterns, anomalies, and abusive behaviors.

3. Rules and policies are applied
   Managed rulesets protect against known attack types, and custom rules enforce application-specific security policies.

4. Threats are blocked or mitigated
   Malicious traffic is blocked, challenged, or rate-limited before it reaches the origin application.

5. Visibility and tuning
   Security teams monitor events, adjust policies, and refine protections without redeploying infrastructure.

What problems does WAFaaS solve?

WAF as a Service addresses several common challenges:

• They help adjust to the growing application attack surface, including APIs and microservices

• They help avoid the operational overhead of managing and scaling traditional WAF appliances

• The prevent delayed patching by providing virtual patching for known vulnerabilities

• They handle traffic spikes and attack bursts that overwhelm fixed-capacity infrastructure

• They provide visibility into Layer 7 attacks and abusive behaviors that traditional WAFs may struggle with

By offloading infrastructure management to the provider, WAFaaS allows teams to focus on policy and risk, not tuning and hardware.

Who should use WAF as a Service?

WAFaaS is a strong fit for:

• Organizations with cloud-hosted or hybrid applications

• Teams practicing DevOps or DevSecOps that need security to move at deployment speed

• SaaS providers and digital businesses with public-facing applications

• Security teams with limited operational resources

• Enterprises modernizing legacy WAF deployments

They are especially useful for environments with highly variable traffic or frequent application changes.

What are WAFaaS key features and capabilities?

Typical WAFaaS platforms offer:

• Managed rulesets for common web and API attacks

• Custom security policies and rule logic

• API protection and schema-aware inspection (provider-dependent)

• Rate limiting and abuse prevention

• Bot detection and mitigation capabilities

• Layer 7 DDoS protection or integration with DDoS services

• Centralized logging, alerting, and analytics

• Integrations with SIEM, SOAR, CI/CD, and ticketing tools

How does a WAF as a Service inspect and filter traffic?

WAFaaS inspects traffic at the application layer (Layer 7) by examining:

• Request headers, URLs, parameters, and bodies

• HTTP methods and protocol compliance

• Behavioral signals such as request frequency and patterns

• Known attack signatures and anomalous behavior

Based on this analysis, the WAF applies policies to:

• Allow legitimate requests

• Block malicious traffic

• Challenge suspicious clients

• Rate-limit abusive sources

Inspection occurs in real time, typically at the edge or close to the application.

How does a cloud-delivered WAF differ from a traditional appliance WAF?

Does WAFaaS protect both web applications and APIs?

Yes. Modern WAFaaS solutions are designed to protect both traditional web applications and APIs. In addition to classic web attack protection, many platforms offer:

• API endpoint discovery

• Schema and method enforcement

• Protection against API-specific abuse and injection attacks  

The depth of API protection varies by vendor, so organizations should evaluate capabilities based on their API usage.

Does WAFaaS help with security and compliance?

WAFaaS can play an important role in meeting security and compliance requirements by:

• Providing protection against OWASP Top 10 vulnerabilities  

• Supporting compliance frameworks such as PCI DSS, SOC 2, and ISO 27001

• Offering centralized logging and reporting for audits

• Enabling compensating controls when vulnerabilities can’t be immediately fixed

While WAFaaS does not replace secure development or patching, it strengthens overall security posture and helps demonstrate due diligence to auditors. WAF as a Service is most effective when used as part of a defense-in-depth strategy, working alongside secure coding practices, vulnerability management, monitoring, and incident response

How Fastly can help

 Fastly offers a Web Application Firewall (WAF) as a managed, edge-based service, known as the Fastly Next-Gen WAF, designed to protect applications and APIs from threats like OWASP Top 10 vulnerabilities with high performance and low latency by inspecting traffic close to users. It's part of their broader edge cloud platform, providing security integrated with their CDN and other services. 

Key aspects of Fastly's WAF service:

• Edge Deployment: Sits on Fastly's global edge network, blocking attacks closer to the user than traditional WAFs.

• Managed Service: Handles rule updates from third parties, open sources, and Fastly's own research, reducing customer burden.

• Comprehensive Protection: Detects and blocks common threats, including SQL injection, XSS, and custom threats, with advanced detection logic.

• Flexible Deployment: Can be deployed at the edge, in the cloud, or even on-premise, offering unified protection across diverse architectures.

• Real-time Visibility: Provides immediate insights into security events and attack mitigation through dashboards and log streaming.

• Integrated Solution: Works seamlessly with Fastly's Content Delivery Network (CDN), DDoS protection, and bot mitigation.