What is a Web Application Firewall (WAF) and Why Do You Need One?

Discover why a web application firewall is a crucial part of a comprehensive security suite that most — if not all — of your clients need.

web application firewall

Cyberattacks are continually growing more sophisticated and diverse, so as a managed services provider (MSP), you need to respond by putting the right defenses in place to protect your clients. One type of solution designed to protect your clients and their businesses is a web application firewall (WAF). But do all of your clients need one? Most likely, the answer is yes.

Why Your Clients Need a Web Application Firewall

To understand why a business needs a web application firewall, you first need to acknowledge that different types of cyberattacks take place at different levels of communication between two endpoints. Using the Open Systems Interconnection (OSI) model, you can see that communication can be categories into seven different layers:

  • Layer 1, Physical: The physical and electrical requirements to operate the system
  • Layer 2, Data link: Handles node-to-node data transfer and error correction from the physical layer
  • Layer 3, Network: Where packet forwarding through routers takes place.
  • Layer 4, Transport: Where decisions occur such as how much data to transmit, at what rate and where it goes
  • Layer 5, Session: Where communication between computers is set up, coordinated and terminated
  • Layer 6, Presentation: Where application format is translated to network format or vice versa — one example of activity at the presentation layer is encryption and decryption of data
  • Layer 7: Application: The layer where users interact with applications

The main difference between a firewall and a web application firewall is that a firewall is usually only associated with protection for the network and transport layers (layers 3 and 4).  A web application firewall, on the other hand, offers protection from layers 3 through 7 — including network, transport, session, presentation, and application layers — so it can provide a better defense against types of cyberattacks executed in those layers.

If your client has a firewall but not web application firewall, it is possible, therefore, for them to become victims of cyberattacks such as distributed denial of service (DDoS), SQL injection, or other OWASP Top Ten Most Critical Web Application Security Risks.

Other Valuable Features of a WAF

In addition to protection from attacks executed at OSI layers 3 through 7, a WAF also has the ability to do more than just control web traffic — it can analyze it. WAFs can stop known threats or use machine learning or other types of artificial intelligence (AI) to spot and flag malicious behaviors.

Also, a WAF can function as a reverse proxy. A reverse proxy sits in front of web servers, intercepting requests from clients; when client machines send requests to a website, it’s the reverse proxy that intercepts them and sends requests to the web server and receives responses — with a reverse proxy, no client ever communicates directly with the origin server. With regard to security, cybercriminals wouldn’t have direct access to the server — they’d have to go through the web application firewall, which makes executing an attack much more difficult.

WAF: A Solution for Our Time

With more and more of your clients conducting business or offering services online, you need to implement the right solutions to protect them. Overlooking the need for any vital part of a comprehensive security solution can leave your clients vulnerable to attacks that can disrupt operations, cause downtime, lead to data breaches — and maybe even the downfall of their businesses. A web application firewall solution is a crucial part of the total security solution your clients need.