Mailbox — the complete, unedited output of the deterministic mcptrustchecker engine v1.10.0, scanned . Every finding, capability tag and score component below is exactly what the engine produced — no AI, no post-processing.
{
"tool": {
"name": "mcptrustchecker",
"version": "1.10.0",
"methodologyVersion": "mcptrustchecker-1.9"
},
"target": {
"id": "https://mailbox.bot/api/mcp",
"source": {
"kind": "http",
"origin": "https://mailbox.bot/api/mcp"
},
"server": {
"name": "mailbox.bot",
"version": "1.0.1"
}
},
"grade": "A",
"score": {
"score": 97,
"threatScore": 100,
"grade": "A",
"band": "A",
"categorySubtotals": {
"injection": 0,
"exfiltration": 0,
"permissions": 0,
"supply-chain": 0,
"network": 0,
"hygiene": 0
},
"vector": [
{
"kind": "client",
"term": "capability-exposure",
"level": "moderate",
"label": "capability blast radius (moderate) — client exposure if the model is manipulated",
"appliedPenalty": 3
},
{
"kind": "client",
"term": "coverage-honesty",
"level": "live",
"label": "inspection depth (live) — how much of the target the scan could see",
"appliedPenalty": 0
}
],
"gatesFired": [],
"methodologyVersion": "mcptrustchecker-1.9"
},
"capability": {
"level": "moderate",
"reasons": [
"ingests untrusted external content (a prompt-injection entry point)",
"can send data / act on an external service"
],
"tags": [
"external-sink",
"untrusted-input"
]
},
"coverage": {
"level": "live",
"inputs": {
"toolSurface": true,
"implementationSource": false,
"packageMetadata": false,
"liveTransport": true
},
"caveats": []
},
"findings": [
{
"ruleId": "MTC-FLOW-005",
"title": "Untrusted input can drive an external action",
"category": "exfiltration",
"severity": "medium",
"confidence": "strong",
"description": "Untrusted-input tools ([list_facility_conversations]) co-exist with external-action tools ([list_inbound_forwarding_addresses, update_webhook, send_outbound_mail, create_test_outbound_mail, advance_test_outbound_mail]). A prompt injection could cause unwanted external actions, though no direct sensitive-data leak path was found.",
"remediation": "Require confirmation for state-changing/egress actions triggered after processing untrusted content.",
"location": {
"kind": "flow",
"name": "list_facility_conversations → list_inbound_forwarding_addresses"
},
"evidence": "untrusted [list_facility_conversations] → sinks [list_inbound_forwarding_addresses, update_webhook, send_outbound_mail, create_test_outbound_mail, advance_test_",
"owasp": "LLM06:2025 Excessive Agency",
"references": [],
"data": {
"untrusted": [
"list_facility_conversations"
],
"sinks": [
"list_inbound_forwarding_addresses",
"update_webhook",
"send_outbound_mail",
"create_test_outbound_mail",
"advance_test_outbound_mail"
]
}
},
{
"ruleId": "MTC-CAP-007",
"title": "Unconstrained URL/host parameter \"webhook_url\" on \"update_webhook\"",
"category": "network",
"severity": "medium",
"confidence": "heuristic",
"description": "Tool \"update_webhook\" takes a URL/host parameter \"webhook_url\" with no allowlist/pattern. An outbound-request tool with an unbounded destination enables SSRF and cloud-metadata access (e.g. 169.254.169.254).",
"remediation": "Allowlist destinations or constrain the parameter; block private/link-local addresses server-side.",
"location": {
"kind": "tool",
"name": "update_webhook",
"field": "inputSchema.properties.webhook_url"
},
"owasp": "LLM06:2025 Excessive Agency",
"data": {
"param": "webhook_url"
}
},
{
"ruleId": "MTC-NET-005",
"title": "Remote HTTP MCP endpoint",
"category": "network",
"severity": "info",
"confidence": "strong",
"description": "Remote endpoint mailbox.bot. MCP Trust Checker does not test server-side authentication/authorization; verify the endpoint requires auth.",
"location": {
"kind": "transport"
}
}
],
"toxicFlows": [
{
"id": "flow-1",
"severity": "medium",
"confidence": "strong",
"untrustedInput": [
"list_facility_conversations"
],
"sensitiveSource": [],
"externalSink": [
"list_inbound_forwarding_addresses",
"update_webhook",
"send_outbound_mail",
"create_test_outbound_mail",
"advance_test_outbound_mail"
],
"selfContained": false,
"description": "Untrusted input can drive an external action even though no sensitive source is exposed."
}
],
"capabilities": [
{
"tool": "get_mailbox",
"tags": [],
"reasons": {}
},
{
"tool": "list_packages",
"tags": [],
"reasons": {}
},
{
"tool": "get_package",
"tags": [],
"reasons": {}
},
{
"tool": "get_package_photos",
"tags": [],
"reasons": {}
},
{
"tool": "request_action",
"tags": [],
"reasons": {}
},
{
"tool": "request_scan",
"tags": [],
"reasons": {}
},
{
"tool": "get_scan_results",
"tags": [],
"reasons": {}
},
{
"tool": "add_tag",
"tags": [],
"reasons": {}
},
{
"tool": "add_note",
"tags": [],
"reasons": {}
},
{
"tool": "create_rule",
"tags": [],
"reasons": {}
},
{
"tool": "register_expected",
"tags": [],
"reasons": {}
},
{
"tool": "get_usage",
"tags": [],
"reasons": {}
},
{
"tool": "list_inbound_forwarding_addresses",
"tags": [
"external-sink"
],
"reasons": {
"external-sink": [
"keyword \"upload_file\""
]
}
},
{
"tool": "list_inbound_mail",
"tags": [],
"reasons": {}
},
{
"tool": "get_inbound_mail",
"tags": [],
"reasons": {}
},
{
"tool": "list_postal_threads",
"tags": [],
"reasons": {}
},
{
"tool": "get_postal_thread",
"tags": [],
"reasons": {}
},
{
"tool": "update_action",
"tags": [],
"reasons": {}
},
{
"tool": "get_mailbox_md",
"tags": [],
"reasons": {}
},
{
"tool": "propose_mailbox_md_edit",
"tags": [],
"reasons": {}
},
{
"tool": "send_facility_message",
"tags": [],
"reasons": {}
},
{
"tool": "list_facility_conversations",
"tags": [
"untrusted-input"
],
"reasons": {
"untrusted-input": [
"keyword \"read_message\""
]
}
},
{
"tool": "get_facility_messages",
"tags": [],
"reasons": {}
},
{
"tool": "update_webhook",
"tags": [
"external-sink"
],
"reasons": {
"external-sink": [
"keyword \"webhook\"",
"parameter \"webhook\""
]
}
},
{
"tool": "send_outbound_mail",
"tags": [
"external-sink"
],
"reasons": {
"external-sink": [
"parameter \"recipient\""
]
}
},
{
"tool": "list_outbound_mail",
"tags": [],
"reasons": {}
},
{
"tool": "get_outbound_mail",
"tags": [],
"reasons": {}
},
{
"tool": "cancel_outbound_mail",
"tags": [],
"reasons": {}
},
{
"tool": "create_test_outbound_mail",
"tags": [
"external-sink"
],
"reasons": {
"external-sink": [
"keyword \"webhook\"",
"parameter \"recipient\""
]
}
},
{
"tool": "advance_test_outbound_mail",
"tags": [
"external-sink"
],
"reasons": {
"external-sink": [
"keyword \"webhook\""
]
}
}
],
"surfaceDigest": "8676f888b85221aa88d86606bfd967230e7eec9473b9b2f593fbbfb01cf7fd3b",
"stats": {
"tools": 30,
"prompts": 0,
"resources": 0,
"findingsBySeverity": {
"critical": 0,
"high": 0,
"medium": 2,
"low": 0,
"info": 1
}
}
}