B2a — the complete, unedited output of the deterministic mcptrustchecker engine v1.9.0, scanned . Every finding, capability tag and score component below is exactly what the engine produced — no AI, no post-processing.
{
"tool": {
"name": "mcptrustchecker",
"version": "1.9.0",
"methodologyVersion": "mcptrustchecker-1.9"
},
"target": {
"id": "b2a-mcp-server",
"source": {
"kind": "package",
"origin": "b2a-mcp-server"
},
"server": {
"name": "b2a-mcp-server"
}
},
"grade": "B",
"score": {
"score": 89,
"threatScore": 96,
"grade": "B",
"band": "B",
"categorySubtotals": {
"injection": 0,
"exfiltration": 0,
"permissions": 0,
"supply-chain": 3.6,
"network": 0,
"hygiene": 0
},
"vector": [
{
"kind": "threat",
"ruleId": "MTC-SUP-005",
"category": "supply-chain",
"severity": "medium",
"confidence": "heuristic",
"rawWeight": 9,
"confidenceMult": 0.4,
"diminishingFactor": 1,
"appliedPenalty": 3.6
},
{
"kind": "client",
"term": "capability-exposure",
"level": "high",
"label": "capability blast radius (high) — client exposure if the model is manipulated",
"appliedPenalty": 6
},
{
"kind": "client",
"term": "verification-discount",
"level": "repo",
"label": "publisher verification (public source) — no provenance, but the source is public and inspectable",
"appliedPenalty": 1
},
{
"kind": "client",
"term": "coverage-honesty",
"level": "source",
"label": "inspection depth (source) — how much of the target the scan could see",
"appliedPenalty": 0
}
],
"gatesFired": [],
"methodologyVersion": "mcptrustchecker-1.9"
},
"capability": {
"level": "high",
"reasons": [
"ingests untrusted external content (a prompt-injection entry point)",
"can send data / act on an external service",
"reads sensitive or local data",
"has a read → egress path (a data-exfiltration surface)",
"untrusted-input, sensitive-source and egress co-exist across tools (toxic-flow surface)"
],
"tags": [
"untrusted-input",
"external-sink",
"sensitive-source"
]
},
"coverage": {
"level": "source",
"inputs": {
"toolSurface": true,
"implementationSource": true,
"packageMetadata": true,
"liveTransport": false
},
"caveats": [
"Tools were statically extracted from the published source (5 recovered), not enumerated from a running server. Tool-poisoning, Unicode-smuggling, capability and toxic-flow analysis ran on this inferred surface, but a mis-parsed registration could be missed or mis-attributed, so tool-derived findings are capped below “confirmed”. To grade the real runtime surface, scan the running server: --command \"npx -y <package>\"."
]
},
"findings": [
{
"ruleId": "MTC-FLOW-002",
"title": "Completed toxic-flow trifecta across tools",
"category": "exfiltration",
"severity": "critical",
"confidence": "strong",
"description": "This server (without client built-ins) exposes a complete data-exfiltration chain: b2a_browse ⇒ b2a_call. Untrusted input is ingested, private data is read, and it can be sent to an external sink — and at least one leg is a direct schema wire (⇒), where a producer's output drops straight into a free-text parameter of the next tool, so the chain needs little agent cooperation. Static analysis proves the primitive exists, not that a specific run will occur.",
"remediation": "Remove one leg of the trifecta: isolate untrusted-input tools from secret-reading tools and from egress tools, or require human approval between them.",
"location": {
"kind": "flow",
"name": "b2a_browse → b2a_call"
},
"owasp": "LLM02:2025 Sensitive Information Disclosure",
"references": [],
"data": {
"untrusted": [
"b2a_browse"
],
"sources": [
"b2a_call"
],
"sinks": [
"b2a_call"
],
"path": [
"b2a_browse",
"b2a_call"
],
"edges": [
{
"from": "b2a_browse",
"to": "b2a_call",
"kind": "schema-wired"
}
],
"wired": true
}
},
{
"ruleId": "MTC-FLOW-003",
"title": "Read-and-egress in one tool: \"b2a_call\"",
"category": "exfiltration",
"severity": "high",
"confidence": "strong",
"description": "Tool \"b2a_call\" can both read sensitive data and send data to an external destination. Even without an explicit untrusted-input leg, this is a single-call data-exfiltration path if the model is ever manipulated.",
"remediation": "Separate reading from sending; require explicit user confirmation before egress of file/secret contents.",
"location": {
"kind": "flow",
"name": "b2a_call"
},
"owasp": "LLM02:2025 Sensitive Information Disclosure",
"references": [],
"data": {
"tags": [
"external-sink",
"sensitive-source"
]
}
},
{
"ruleId": "MTC-CAP-007",
"title": "Unconstrained URL/host parameter \"url\" on \"b2a_call\"",
"category": "network",
"severity": "medium",
"confidence": "heuristic",
"description": "Tool \"b2a_call\" takes a URL/host parameter \"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": "b2a_call",
"field": "inputSchema.properties.url"
},
"owasp": "LLM06:2025 Excessive Agency",
"data": {
"param": "url"
}
},
{
"ruleId": "MTC-SUP-005",
"title": "Near-miss of exa-mcp-server (edit distance 2)",
"category": "supply-chain",
"severity": "medium",
"confidence": "heuristic",
"description": "\"b2a-mcp-server\" is edit-distance 2 from the package \"exa-mcp-server\". Verify this is the intended package.",
"remediation": "Confirm you meant \"exa-mcp-server\". Install packages only from their documented, official name.",
"location": {
"kind": "package",
"name": "b2a-mcp-server"
},
"owasp": "LLM03:2025 Supply Chain",
"references": [
"https://github.com/ossf/package-analysis",
"https://owasp.org/www-project-top-10-ci-cd-security-risks/"
],
"data": {
"candidate": "b2a-mcp-server",
"target": "exa-mcp-server"
}
}
],
"toxicFlows": [
{
"id": "flow-1",
"severity": "critical",
"confidence": "strong",
"untrustedInput": [
"b2a_browse"
],
"sensitiveSource": [
"b2a_call"
],
"externalSink": [
"b2a_call"
],
"selfContained": false,
"path": [
"b2a_browse",
"b2a_call"
],
"pathWired": true,
"description": "A cross-tool exfiltration chain exists: b2a_browse ⇒ b2a_call."
},
{
"id": "flow-2",
"severity": "high",
"confidence": "strong",
"untrustedInput": [],
"sensitiveSource": [
"b2a_call"
],
"externalSink": [
"b2a_call"
],
"selfContained": true,
"description": "Tool \"b2a_call\" both reads sensitive data and can send it externally."
}
],
"capabilities": [
{
"tool": "b2a_discover",
"tags": [],
"reasons": {}
},
{
"tool": "b2a_verify",
"tags": [],
"reasons": {}
},
{
"tool": "b2a_enhance",
"tags": [],
"reasons": {}
},
{
"tool": "b2a_browse",
"tags": [
"untrusted-input"
],
"reasons": {
"untrusted-input": [
"keyword \"browse\""
]
}
},
{
"tool": "b2a_call",
"tags": [
"external-sink",
"sensitive-source"
],
"reasons": {
"external-sink": [
"keyword \"http_post\""
],
"sensitive-source": [
"parameter \"secret\""
]
}
}
],
"surfaceDigest": "746845df59729eb06790aa2369bb3ebef8c6966586a209b3aa9dc9e3796eed45",
"stats": {
"tools": 5,
"prompts": 0,
"resources": 0,
"findingsBySeverity": {
"critical": 1,
"high": 1,
"medium": 2,
"low": 0,
"info": 0
}
}
}