Explanation

AWS WAF (Web Application Firewall) is the correct answer because:

• SQL Injection Protection: AWS WAF provides specific rules and filters to detect and block SQL injection attacks, which are a common web application vulnerability
• Web Application Focus: WAF is specifically designed to protect web applications from common exploits like SQL injection, cross-site scripting (XSS), and other OWASP Top 10 threats
• Managed Rules: AWS WAF offers managed rule groups that include SQL injection protection rules

Why other options are incorrect:

• AWS Shield: Provides DDoS protection but does not specifically address SQL injection attacks
• Network ACLs: Operate at the subnet level and control traffic based on IP addresses and ports, not application-level content
• Security Groups: Act as virtual firewalls for EC2 instances at the instance level, controlling traffic based on protocols and ports, not application payload content

AWS WAF inspects HTTP/HTTPS requests and can block malicious SQL code before it reaches your web applications.