The Bedrock AgentCore Starter Toolkit fails to verify S3 bucket ownership, creating a critical security gap that could lead to unauthorized data access or bucket hijacking.

This vulnerability stems from a missing S3 ownership verification check within the AgentCore Starter Toolkit. An unauthenticated attacker could potentially exploit this to interact with S3 buckets they do not own, leading to unauthorized data manipulation or exfiltration.

The lack of ownership verification directly threatens the confidentiality and integrity of data stored in Amazon S3. Given the CVSS score of 7.5, this vulnerability could lead to unauthorized access to sensitive intellectual property or customer data, resulting in regulatory non-compliance and significant financial liability.

Immediate Action: Upgrade the Bedrock AgentCore Starter Toolkit to version v0 or later immediately to implement the required ownership verification logic.

Proactive Monitoring: Review AWS CloudTrail logs for unusual S3 bucket access patterns or API calls originating from the AgentCore environment.

Compensating Controls: Apply restrictive IAM policies and S3 Bucket Policies that enforce the "ResourceAccount" condition to ensure requests are only directed to buckets within the authorized AWS account.

Public Exploit Available: false

Organizations utilizing the Bedrock AgentCore Starter Toolkit must apply the latest updates immediately. Failure to verify bucket ownership is a fundamental security oversight that must be corrected to prevent unauthorized third parties from interacting with internal cloud storage.