AWS AgentCore Harness Ships Built-In Shell and Identity Vault Tools
Unit 42 researchers have published a detailed analysis of AWS AgentCore Harness's default configuration, specifically how its built-in shell tool and AgentCore Identity credential vault interact at runtime when credentials are resolved to plaintext. The research closes a visibility gap for defenders by providing concrete, operationally grounded guidance on scoping allowedTools, applying least-privilege to Identity vault service accounts, and monitoring outbound traffic from harness containers. What remains is an organisational maturity question: operators must actively opt into these controls rather than relying on secure defaults, meaning the benefit is fully realised only by teams with the awareness and tooling to enforce runtime scoping.