Which AWS service or feature provides this functionality?

Explanations:

AWS WAF (Web Application Firewall) is specifically designed to protect web applications from common web exploits like SQL injection by allowing users to create custom rules.

Network ACLs (Access Control Lists) operate at the subnet level and control inbound and outbound traffic but do not provide specific protections against SQL injection attacks.

Security groups are virtual firewalls for instances to control inbound and outbound traffic but do not inspect or filter application layer requests to prevent SQL injection.

AWS Trusted Advisor provides best practices and insights for AWS account optimization but does not offer specific protections against SQL injection attacks.