A company needs to block SQL injection attacks.

AWS WAF is a web application firewall that helps protect web applications from common web exploits, such as SQL injection attacks. It allows customers to create custom rules that block malicious requests. AWS Shield is a managed service that protects against distributed denial of service (DDoS) attacks, not SQL injection attacks. Network ACLs and security groups are network-level security features that filter traffic based on IP addresses and ports, not web requests or SQL queries. References: [AWS WAF], [AWS Shield], [Network ACLs], [Security groups]