Misconfigured AWS Private API Gateways can be exploited by attackers from external AWS accounts due to overly permissive resource-based policies. This vulnerability allows them to access internal resources and potentially launch further attacks, emphasizing the need for strict policy configurations and monitoring. Proper security measures, such as limiting access to specific VPCs and implementing API authentication, are crucial to protect against these threats.

The article discusses how to secure a REST API Gateway by restricting access to only requests that come through a CloudFront distribution. It outlines the necessary configurations and steps to implement this security measure effectively, enhancing the API's protection against unauthorized access.