AWS Bedrock Agent Privilege Escalation via Overprivileged IAM Roles
Amazon Bedrock AgentCore's starter toolkit automatically generates IAM roles with excessive permissions that violate the principle of least privilege, creating a pathway for privilege escalation attacks. When developers use these default configurations in production environments, a single compromised agent can gain unauthorized access to other agents' data, container images, and sensitive resources across the AWS account. This vulnerability demonstrates the critical importance of reviewing and customizing auto-generated security configurations rather than deploying them as-is. AWS has acknowledged the issue by updating documentation to clarify that default roles are intended only for development and testing environments.
Tactical Insight
Immediate actions
- Review all existing Bedrock Agent IAM roles and remove unnecessary permissions
- Replace auto-generated IAM roles with custom roles following least privilege principles
- Audit current production deployments using default Bedrock configurations
Long-term improvements
- Establish mandatory security reviews for all auto-generated cloud configurations before production deployment
- Implement IAM policy validation tools to detect overprivileged roles during deployment
- Create organization-specific templates for Bedrock agents with minimal required permissions
Monitoring measures
- Enable CloudTrail logging to monitor unusual cross-agent access patterns
- Set up alerts for privilege escalation attempts and unauthorized resource access