AWS Security Blog

Tag: AWS Lambda

How to Detect and Automatically Revoke Unintended IAM Access with Amazon CloudWatch Events

Update on October 24, 2018: Note that if you do not author the Lambda function correctly, this setup can create an infinite loop (in this case, a rule that is fired repeatedly, which can impact your AWS resources and cause higher than expected charges to your account). The example Lambda function I provide in Step […]

How to Reduce Security Threats and Operating Costs Using AWS WAF and Amazon CloudFront

Note from July 3, 2017: The solution in this post has been integrated into AWS WAF Security Automations, and AWS maintains up-to-date solution code in the companion GitHub repository.   Some Internet operations trust that clients are “well behaved.” As an operator of a publicly accessible web application, for example, you have to trust that the clients […]

How to Use AWS WAF to Block IP Addresses That Generate Bad Requests

Note from July 3, 2017: The solution in this post has been integrated into AWS WAF Security Automations, and AWS maintains up-to-date solution code in the companion GitHub repository.   Internet-facing web applications are frequently scanned and probed by various sources, sometimes for good and other times to identify weaknesses. It takes some sleuthing to determine the […]

Register for and Attend This March 2 Webinar—Using AWS WAF and Lambda for Automatic Protection

Update: The video and slides from the webinar are now available. As part of the AWS Webinar Series, AWS will present Using AWS WAF and Lambda for Automatic Protection on Wednesday, March 2. This webinar will start at 10:00 A.M. and end at 11:00 A.M. Pacific Time (UTC-8). AWS WAF Software Development Manager Nathan Dye […]

How to Configure Rate-Based Blacklisting with AWS WAF and AWS Lambda

Note from July 3, 2017: The solution in this post has been integrated into AWS WAF Security Automations, and AWS maintains up-to-date solution code in the companion GitHub repository.   One security challenge you may have faced is how to prevent your web servers from being flooded by unwanted requests, or scanning tools such as bots and […]

How to Automatically Update Your Security Groups for Amazon CloudFront and AWS WAF by Using AWS Lambda

July 29, 2025: This blog post is outdated. Use CloudFront’s managed prefix list for Security Groups instead of the Lambda solution. CloudFront now supports VPC origins, allowing secure connectivity to private VPC resources. For details on managed prefix lists, see this post. For VPC origins implementation guide, refer to this post. April 1, 2021: Before […]

How to Receive Alerts When Specific APIs Are Called by Using AWS CloudTrail, Amazon SNS, and AWS Lambda

Let’s face it—not all APIs were created equal. For example, you may be really interested in knowing when any of your Amazon EC2 instances are terminated (ec2:TerminateInstance), but less interested when an object is put in an Amazon S3 bucket (s3:PutObject). In this example, you can delete an object, but you can’t bring back that […]