Gmail — the complete, unedited output of the deterministic mcptrustchecker engine v1.13.0, scanned . Every finding, capability tag and score component below is exactly what the engine produced — no AI, no post-processing.
{
"tool": {
"name": "mcptrustchecker",
"version": "1.13.0",
"methodologyVersion": "mcptrustchecker-1.13"
},
"target": {
"id": "gmail-mcp-server",
"source": {
"kind": "package",
"origin": "gmail-mcp-server"
},
"server": {
"name": "gmail-mcp-server"
}
},
"grade": "A",
"score": {
"score": 91,
"threatScore": 99,
"grade": "A",
"band": "A",
"categorySubtotals": {
"injection": 0,
"exfiltration": 0,
"permissions": 0,
"supply-chain": 1.2,
"network": 0,
"hygiene": 0
},
"vector": [
{
"kind": "threat",
"ruleId": "MTC-SUP-010",
"category": "supply-chain",
"severity": "low",
"confidence": "heuristic",
"rawWeight": 3,
"confidenceMult": 0.4,
"diminishingFactor": 1,
"appliedPenalty": 1.2
},
{
"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": "none",
"label": "publisher verification (unlinked) — no provenance/repo link, but the shipped source was fully read",
"appliedPenalty": 2
},
{
"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-1.13"
},
"capability": {
"level": "high",
"reasons": [
"ingests untrusted external content (a prompt-injection entry point)",
"can send data / act on an external service",
"can execute shell commands or code"
],
"tags": [
"external-sink",
"untrusted-input",
"code-exec"
]
},
"coverage": {
"level": "source",
"inputs": {
"toolSurface": true,
"implementationSource": true,
"packageMetadata": true,
"liveTransport": false
},
"caveats": [
"Tools were statically extracted from the published source (16 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-SRC-002",
"title": "Shell/command execution in server code (bin/cli.js)",
"category": "permissions",
"severity": "high",
"confidence": "strong",
"description": "In the server's implementation (`bin/cli.js:5`): Spawning a shell/process is command-execution capability; with unsanitized tool input it is command injection / RCE. This is read from the code itself — not from the tool description — so a poisoned server cannot hide it behind honest-looking metadata.",
"remediation": "Review this call path: confirm it never receives unsanitized tool input, constrain it, or remove it. Treat a server whose code reaches these sinks as high-capability regardless of what its tools claim.",
"location": {
"kind": "server",
"name": "bin/cli.js"
},
"evidence": "import { spawn } from 'child_process'; import fs from 'fs'; import readline from 'readline'; import os from 'os'; // D",
"owasp": "LLM05:2025 Improper Output Handling",
"data": {
"rule": "MTC-SRC-002",
"file": "bin/cli.js",
"line": 5,
"nonRuntime": false
}
},
{
"ruleId": "MTC-FLOW-005",
"title": "Untrusted input can drive an external action",
"category": "exfiltration",
"severity": "medium",
"confidence": "strong",
"description": "Untrusted-input tools ([gmail_read_email, gmail_get_attachment]) co-exist with external-action tools ([gmail_send_email]). 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": "gmail_read_email → gmail_send_email"
},
"evidence": "untrusted [gmail_read_email, gmail_get_attachment] → sinks [gmail_send_email]",
"owasp": "LLM06:2025 Excessive Agency",
"references": [],
"data": {
"untrusted": [
"gmail_read_email",
"gmail_get_attachment"
],
"sinks": [
"gmail_send_email"
]
}
},
{
"ruleId": "MTC-SUP-010",
"title": "Package runs install-time scripts (postinstall)",
"category": "supply-chain",
"severity": "low",
"confidence": "heuristic",
"description": "\"gmail-mcp-server\" executes postinstall script(s) at install time. An install hook runs at install time; most are routine build/setup, but review what it does before trusting it.",
"remediation": "Review the scripts; install with --ignore-scripts where possible and vet what they do.",
"location": {
"kind": "package",
"name": "gmail-mcp-server"
},
"evidence": "node install.js",
"owasp": "LLM03:2025 Supply Chain",
"references": [
"https://github.com/ossf/package-analysis",
"https://owasp.org/www-project-top-10-ci-cd-security-risks/"
],
"data": {
"scripts": [
"postinstall"
]
}
},
{
"ruleId": "MTC-SUP-011",
"title": "Package declares no source repository",
"category": "supply-chain",
"severity": "info",
"confidence": "strong",
"description": "\"gmail-mcp-server\" declares no repository URL, so its published artifact cannot be compared against reviewable source.",
"remediation": "Prefer packages that link to public, reviewable source.",
"location": {
"kind": "package",
"name": "gmail-mcp-server"
}
}
],
"toxicFlows": [
{
"id": "flow-1",
"severity": "medium",
"confidence": "strong",
"untrustedInput": [
"gmail_read_email",
"gmail_get_attachment"
],
"sensitiveSource": [],
"externalSink": [
"gmail_send_email"
],
"selfContained": false,
"description": "Untrusted input can drive an external action even though no sensitive source is exposed."
}
],
"capabilities": [
{
"tool": "gmail_send_email",
"tags": [
"external-sink"
],
"reasons": {
"external-sink": [
"keyword \"send_email\""
]
}
},
{
"tool": "gmail_read_email",
"tags": [
"untrusted-input"
],
"reasons": {
"untrusted-input": [
"keyword \"read_email\""
]
}
},
{
"tool": "gmail_search_emails",
"tags": [],
"reasons": {}
},
{
"tool": "analyze_conversation",
"tags": [],
"reasons": {}
},
{
"tool": "gmail_mark_email",
"tags": [],
"reasons": {}
},
{
"tool": "gmail_move_email",
"tags": [],
"reasons": {}
},
{
"tool": "gmail_delete_email",
"tags": [],
"reasons": {}
},
{
"tool": "gmail_list_attachments",
"tags": [],
"reasons": {}
},
{
"tool": "gmail_get_attachment",
"tags": [
"untrusted-input"
],
"reasons": {
"untrusted-input": [
"keyword \"download\""
]
}
},
{
"tool": "gmail_draft",
"tags": [],
"reasons": {}
},
{
"tool": "gmail_logout",
"tags": [],
"reasons": {}
},
{
"tool": "gmail_system_status",
"tags": [],
"reasons": {}
},
{
"tool": "gmail_performance_metrics",
"tags": [],
"reasons": {}
},
{
"tool": "gmail_authenticate_user",
"tags": [],
"reasons": {}
},
{
"tool": "gmail_manage_session",
"tags": [],
"reasons": {}
},
{
"tool": "gmail_authenticate",
"tags": [],
"reasons": {}
}
],
"surfaceDigest": "bd22c7b3cadcc141fd652c4aa8dd2514e59356bd0c2768d845a9a1741c4eea55",
"stats": {
"tools": 16,
"prompts": 0,
"resources": 0,
"findingsBySeverity": {
"critical": 0,
"high": 1,
"medium": 1,
"low": 1,
"info": 1
}
}
}