AWS AgentCore security undone by prompt requesting credentials

Bob, possibly the same Bob whose conversations with Alice draw so much interest from eavesdropping Eve, was browsing a site we'll call TechHub. The site hosts an AI agent served by Amazon Bedrock AgentCore. Bob asked the agent for help understanding the content of a URL, a credential endpoint – in raw JSON, if you don't mind. The endpoint returned data from the Instance Metadata Service (IMDS), which provides metadata about cloud instances and VMs at providers like AWS, Azure, and Google Cloud Platform. The metadata includes details like region and availability zone, subnets, system images, security groups, public keys injected during spawning, but also potentially more sensitive details like user data and security tokens. IMDSv2 addresses some of these risks, but back when Bob was browsing late last year, Bedrock AgentCore still used IMDSv1. The metadata provided to Bob by the helpful agent contained the agent's temporary credentials. …