What would a Web Application Firewall typically inspect and filter?

A Web Application Firewall (WAF) is specifically designed to monitor, filter, and protect web applications by inspecting HTTP and HTTPS traffic. The primary role of a WAF is to analyze requests and responses between clients and web servers in order to identify and block potential threats, such as cross-site scripting (XSS) and SQL injection attacks.

HTTP and HTTPS are the protocols utilized for web traffic. The distinction between them lies in HTTPS incorporating encryption through SSL/TLS, providing a secure transmission over the internet. Since WAFs operate at the application layer of the OSI model, they focus on this type of communication to safeguard web applications from numerous vulnerabilities that can be exploited through these protocols.

By inspecting this traffic, a WAF can apply security rules to ensure that only legitimate requests are processed and that potentially harmful requests are blocked before they reach the server, enhancing the overall security posture of the web application.

The other options do not accurately reflect the primary functionality of a WAF; for instance, FTP traffic concerns file transfers rather than web application interactions, DNS relates to name resolution rather than direct interaction with web applications, and incoming and outgoing emails fall under the domain of email security systems rather than a WAF. Thus, the emphasis on HTTP and HTTPS