Web app firewall

Web app firewall

A WAF (web application firewall) is a filter that protects against HTTP application attacks. It inspects HTTP traffic before it reaches your application and protects your server by filtering out threats that could damage your site functionality or compromise data.

As companies and users increasingly rely on web applications, such as web-based email or e-commerce functionality, application-layer attacks pose a greater risk to productivity and security. Therefore, a WAF is crucial to protect against rapidly emerging web security threats.

A WAF protects against malicious attacks, such as:

  • SQL injection – a hacking technique used to extract sensitive information from a database.
  • Malicious file execution – a harmful technique which allows a person to execute code remotely after a user accepts a malicious file.
  • Cross-site scripting – when malicious script is injected into the code of an otherwise trusted website, allowing potentially sensitive user data such as cookies to be accessed.

A web application firewall is deployed in front of web applications and analyzes bi-directional web-based (HTTP) traffic – inspecting both GET and POST requests – detecting and blocking anything malicious.

WAF performs a deep inspection of every request and response for all common forms of web traffic. This inspection helps the WAF to identify and block threats, preventing them from reaching the server.


Using a WAF provides a scalable platform that can be accessed globally, helping to protect against multiple threats for large web applications around the world.

A WAF enables users to:

  • Reduce the risk of downtime, data theft and security breaches with a WAF that can scale to protect against the largest DoS and DDoS attacks
  • Ensure high performance even during attacks
  • Defend against new and emerging threats
  • Minimize costs of cloud security by avoiding the need for expensive dedicated hardware