Under the AWS shared responsibility model, which of these tasks is the customer's responsibility?

The AWS shared responsibility model dictates that AWS is responsible for security of the cloud, while the customer is responsible for security in the cloud. Patching the guest operating system on an Amazon EC2 instance falls under the customer's responsibility for security in the cloud, as it relates to the operating system and applications they deploy. AWS is responsible for the underlying infrastructure. Controlling physical access to an AWS data center and controlling access to underlying AWS hardware are both AWS responsibilities (security of the cloud). Patching the host operating system for Amazon S3 is also an AWS responsibility, as S3 is a fully managed service where AWS manages the underlying infrastructure and host OS.