Which AWS service or feature can be used to block SQL injection attacks?

AWS WAF (Web Application Firewall) is a service that helps protect web applications from common web exploits that could affect application availability, compromise security, or consume excessive resources. It allows you to create custom rules to block specific attack patterns, including SQL injection. AWS Shield provides DDoS protection but doesn't specifically target application-layer attacks like SQL injection. Network ACLs (Access Control Lists) operate at the subnet level and filter traffic based on IP addresses and ports, not application-layer content. Security groups act as virtual firewalls for EC2 instances and control inbound/outbound traffic at the instance level, also not inspecting application-layer content for SQL injection patterns.