What does a web application firewall (WAF) protect against?

A web application firewall (WAF) is specifically designed to protect web applications by filtering and monitoring HTTP traffic to and from those applications. This is essential because web applications can be vulnerable to various attacks, including SQL injection, cross-site scripting, and other threats that exploit weaknesses in application code. By analyzing the incoming and outgoing traffic, a WAF can identify potentially harmful requests and deny them before they reach the web server, thus safeguarding sensitive data and maintaining the application's integrity.

The focus of a WAF is on web-based threats and vulnerabilities, which distinguishes it from other types of firewalls that might protect whole networks or systems at different levels. The functionality of a WAF in filtering and monitoring traffic is crucial for maintaining the security posture of web applications, making it a vital tool for organizations with an online presence. This ability to actively inspect and manage web traffic is what sets WAFs apart as a critical layer of defense for web applications.