{ "role": "vulnerable", "attempt": 1, "src": "/pruva/project-cache/build/aws-api-mcp-server-cve-2026-16584/vuln-src", "cli_entrypoint": [ "/pruva/project-cache/build/aws-api-mcp-server-cve-2026-16584/venv/bin/python", "-m", "awslabs.aws_api_mcp_server.server" ], "policy_file": "/tmp/aws-api-mcp-vulnerable-1-60c637gt/.aws/aws-api-mcp/mcp-security-policy.json", "configured_denyList": [ "aws sts get-caller-identity" ], "forced_startup_failure": "invalid proxy for read-operations ServiceReferenceUrlsByService requests", "requested_tool_command": "aws sts get-caller-identity --endpoint-url http://127.0.0.1:37943", "server_started": true, "mcp_initialized": true, "tool_call_completed": true, "fake_aws_boundary_reached": true, "policy_denial_observed": false, "startup_fail_closed": false, "server_log": "logs/repro/vulnerable_attempt_1_server.log", "fake_aws_calls": [ { "method": "POST", "path": "/", "headers": { "Accept-Encoding": "identity", "Content-Type": "application/x-www-form-urlencoded; charset=utf-8", "User-Agent": "Boto3/1.43.53 md/Botocore#1.43.53 md/awscrt#0.36.0 ua/2.1 os/linux#7.0.14-arch1-1 md/arch#x86_64 lang/python#3.14.4 md/pyimpl#CPython m/F,Z,e,b,N cfg/retry-mode#adaptive Botocore/1.43.53 md/awslabs#mcp#aws-api-mcp-server#1.3.47 md/via/AWS-API-MCP MCPClient/mcp#0.1.0 cfg/ro#0 cfg/consent#0 cfg/scripts#0 cfg/file-access#workdir", "host": "127.0.0.1:37943", "X-Amz-Security-Token": "pruva-session-token", "X-Amz-Date": "20260727T013057Z", "Authorization": "AWS4-HMAC-SHA256 Credential=AKIAPRUVAEXAMPLE/20260727/us-east-1/sts/aws4_request, SignedHeaders=content-type;host;x-amz-date;x-amz-security-token, Signature=76302fe4d3deb36a9b8e10e766c2f16d63392d7ccce1099396276685cb2b2c89", "amz-sdk-invocation-id": "74637f43-1600-48a5-aa1b-91e6b68e9878", "amz-sdk-request": "attempt=1", "Content-Length": "43" }, "body": "Action=GetCallerIdentity&Version=2011-06-15" } ], "tool_result_text": "CallToolResult(meta={'fastmcp': {'wrap_result': True}}, content=[TextContent(type='text', text='[{\"cli_command\":\"aws sts get-caller-identity --endpoint-url http://127.0.0.1:37943\",\"response\":{\"error\":null,\"status_code\":200,\"error_code\":null,\"pagination_token\":null,\"as_json\":\"{\\\\\"UserId\\\\\": \\\\\"PRUVA\\\\\", \\\\\"Account\\\\\": \\\\\"123456789012\\\\\", \\\\\"Arn\\\\\": \\\\\"arn:aws:iam::123456789012:user/pruva\\\\\", \\\\\"ResponseMetadata\\\\\": {\\\\\"RequestId\\\\\": \\\\\"pruva-request\\\\\", \\\\\"HTTPStatusCode\\\\\": 200, \\\\\"HTTPHeaders\\\\\": {\\\\\"server\\\\\": \\\\\"BaseHTTP/0.6 Python/3.14.4\\\\\", \\\\\"date\\\\\": \\\\\"Mon, 27 Jul 2026 01:30:57 GMT\\\\\", \\\\\"content-type\\\\\": \\\\\"text/xml\\\\\", \\\\\"content-length\\\\\": \\\\\"329\\\\\"}, \\\\\"RetryAttempts\\\\\": 0}}\"},\"metadata\":{\"service\":\"sts\",\"service_full_name\":\"AWS Security Token Service\",\"operation\":\"GetCallerIdentity\",\"region_name\":\"us-east-1\"},\"validation_failures\":null,\"missing_context_failures\":null,\"failed_constraints\":[]}]', annotations=None, meta=None)], structuredContent={'result': [{'cli_command': 'aws sts get-caller-identity --endpoint-url http://127.0.0.1:37943', 'response': {'error': None, 'status_code': 200, 'error_code': None, 'pagination_token': None, 'as_json': '{\"UserId\": \"PRUVA\", \"Account\": \"123456789012\", \"Arn\": \"arn:aws:iam::123456789012:user/pruva\", \"ResponseMetadata\": {\"RequestId\": \"pruva-request\", \"HTTPStatusCode\": 200, \"HTTPHeaders\": {\"server\": \"BaseHTTP/0.6 Python/3.14.4\", \"date\": \"Mon, 27 Jul 2026 01:30:57 GMT\", \"content-type\": \"text/xml\", \"content-length\": \"329\"}, \"RetryAttempts\": 0}}'}, 'metadata': {'service': 'sts', 'service_full_name': 'AWS Security Token Service', 'operation': 'GetCallerIdentity', 'region_name': 'us-east-1'}, 'validation_failures': None, 'missing_context_failures': None, 'failed_constraints': []}]}, isError=False)", "exception": null, "server_log_tail": "2026-07-27 01:30:57.840 | INFO | __main__:main:430 - CWD: /tmp/aws-api-mcp/workdir\n2026-07-27 01:30:57.841 | INFO | __main__:main:438 - AWS_REGION: us-east-1\n2026-07-27 01:30:57.843 | ERROR | awslabs.aws_api_mcp_server.core.metadata.read_only_operations_list:__init__:56 - Error retrieving the service reference document: HTTPSConnectionPool(host='servicereference.us-east-1.amazonaws.com', port=443): Max retries exceeded with url: / (Caused by ProxyError('Unable to connect to proxy', NewConnectionError(\"HTTPSConnection(host='127.0.0.1', port=9): Failed to establish a new connection: [Errno 111] Connection refused\")))\n2026-07-27 01:30:57.843 | WARNING | __main__:main:444 - Failed to load read operations index: Error retrieving the service reference document: HTTPSConnectionPool(host='servicereference.us-east-1.amazonaws.com', port=443): Max retries exceeded with url: / (Caused by ProxyError('Unable to connect to proxy', NewConnectionError(\"HTTPSConnection(host='127.0.0.1', port=9): Failed to establish a new connection: [Errno 111] Connection refused\")))\n\n\n\u256d\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u256e\n\u2502 \u2502\n\u2502 \u2502\n\u2502 \u2584\u2580\u2580 \u2584\u2580\u2588 \u2588\u2580\u2580 \u2580\u2588\u2580 \u2588\u2580\u2584\u2580\u2588 \u2588\u2580\u2580 \u2588\u2580\u2588 \u2502\n\u2502 \u2588\u2580 \u2588\u2580\u2588 \u2584\u2584\u2588 \u2588 \u2588 \u2580 \u2588 \u2588\u2584\u2584 \u2588\u2580\u2580 \u2502\n\u2502 \u2502\n\u2502 \u2502\n\u2502 \u2502\n\u2502 FastMCP 3.4.4 \u2502\n\u2502 https://gofastmcp.com \u2502\n\u2502 \u2502\n\u2502 \ud83d\udda5 Server: AWS-API-MCP, 3.4.4 \u2502\n\u2502 \ud83d\ude80 Deploy free: https://horizon.prefect.io \u2502\n\u2502 \u2502\n\u2570\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u2500\u256f\n\n\n[07/27/26 01:30:57] INFO Starting MCP server 'AWS-API-MCP' transport.py:241\n with transport 'stdio' \n DEBUG [AWS-API-MCP] Handler called: mcp_operations.py:108\n list_tools \n DEBUG [AWS-API-MCP] Handler called: mcp_operations.py:211\n call_tool call_aws with \n {'cli_command': 'aws sts \n get-caller-identity \n --endpoint-url \n http://127.0.0.1:37943'} \n2026-07-27 01:30:57.911 | INFO | __main__:call_aws_helper:315 - Attempting to execute AWS CLI command: aws sts get-caller-identity *parameters redacted*\n2026-07-27 01:30:57.915 | INFO | awslabs.aws_api_mcp_server.core.common.helpers:operation_timer:39 - Interpreting operation sts.get_caller_identity for region us-east-1\n2026-07-27 01:30:57.936 | INFO | awslabs.aws_api_mcp_server.core.common.helpers:operation_timer:43 - Operation sts.get_caller_identity interpreted in 0.021185892168432474 seconds\n DEBUG [AWS-API-MCP] Handler called: mcp_operations.py:108\n list_tools \n", "startup_failure_observed": true }