Here is a summary of the key points from the blog post in complete sentences:

The previous blog post covered common vulnerabilities in AWS Lambda functions and best practices for securing them. This article applies that theory to concrete examples of vulnerable serverless applications from the OWASP Damn Vulnerable Serverless Application (DVSA). It explores exploiting event injection vulnerabilities in the DVSA to gain unauthorized access and execute malicious code. The effectiveness of AWS security tools like AWS WAF and Amazon Inspector in detecting and preventing these vulnerabilities is also evaluated. Hands-on demonstrations show how the DVSA Order Manager function can be hacked to steal environment variables with AWS credentials using event injection. Tests found AWS WAF with default rules did not block the JavaScript code injection, but Amazon Inspector successfully identified critical vulnerabilities in both package dependencies and custom code. The exploration underscores the importance of proper input validation, secure deserialization, and regular scanning to protect serverless applications.