Understanding, Abusing and Monitoring AWS AppStream 2.0

Tech1 October 6, 2022 2:45 pm - 3:45 pm Feedback     

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Rodrigo Montoro

Amazon Web Services (AWS) is a complex ecosystem with hundreds of different services. In the case of a security breach or compromised credentials, attackers look for ways to abuse the customer’s configuration of services with their compromised credentials, as the credentials are often granted more IAM permissions than is usually needed. Most research to date has focused on the core AWS services, such as, S3, EC2, IAM, CodeBuild, Lambda, KMS, etc. In our research, we present our analysis on a previously overlooked attack surface that is ripe for abuse in the wrong hands – an AWS Service called Amazon AppStream 2.0.

Amazon AppStream 2.0 is a fully managed desktop service that provides users with instant access to their desktop applications from anywhere. Using AppStream 2.0, you can add your desktop applications to a virtual machine and share access to the VM by sharing a link – without requiring any credentials, you can share an image (an attack toolset) with a target account without needing any approval from the other side or attach some privileged role to an image and get those credentials.

In this talk, you’ll learn about how AppStream works, how misconfigurations and excessive IAM permissions can be abused to compromise your AWS environment and allow attackers to control your entire AWS account. We’ll cover tactics such as persistence, lateral movement, exfiltration, social engineering, and privilege escalation. We will also cover the key indicators of compromise for security incidents in AppStream and how to prevent these abuse cases, showing how excessive privileges without great monitoring could become a nightmare in your Cloud Security posture, making possible attackers control your AWS account.