Which type of firewall can identify and filter out malicious traffic using sophisticated rules, specifically for web-based attacks?

The Web Application Firewall (WAF) is specifically designed to protect web applications by filtering and monitoring HTTP traffic between a web application and the internet. It employs sophisticated rules and policies to identify and block malicious traffic that targets web-based applications, such as SQL injection, cross-site scripting (XSS), and other common web vulnerabilities. WAFs are tailored to understand the nuances of web traffic and can dynamically apply rules based on patterns or behaviors indicative of potential attacks, making them highly effective for safeguarding web environments.

In contrast, the other options focus on protecting different types of traffic or systems. DDoS Protection is aimed at mitigating distributed denial-of-service attacks and primarily focuses on keeping services available during an attack rather than filtering specific web-based vulnerabilities. A traditional firewall is designed to allow or block network traffic based on basic rules but lacks the deep inspection capabilities necessary to analyze HTTP requests and responses effectively. Email Security is concerned with protecting email communications and does not interact with web traffic in the same way as a WAF does. This specificity and effectiveness in handling web attacks is what makes the Web Application Firewall the correct answer.