Claude Code Tailscale — 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": "claude-code-tailscale",
"source": {
"kind": "package",
"origin": "claude-code-tailscale"
},
"server": {
"name": "claude-code-tailscale"
}
},
"grade": "A",
"score": {
"score": 93,
"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": "source",
"label": "publisher verification (provenance) — cryptographic build provenance ties the artifact to its source",
"appliedPenalty": 0
},
{
"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",
"can execute shell commands or code"
],
"tags": [
"untrusted-input",
"external-sink",
"code-exec"
]
},
"coverage": {
"level": "source",
"inputs": {
"toolSurface": true,
"implementationSource": true,
"packageMetadata": true,
"liveTransport": false
},
"caveats": [
"Tools were statically extracted from the published source (20 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 (dist/tshelper.js)",
"category": "permissions",
"severity": "high",
"confidence": "strong",
"description": "In the server's implementation (`dist/tshelper.js:7`): 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": "dist/tshelper.js"
},
"evidence": "rt { spawn } from \"node:child_process\"; import { once } from \"node:events\"; import { createInterface } from \"node:readli",
"owasp": "LLM05:2025 Improper Output Handling",
"data": {
"rule": "MTC-SRC-002",
"file": "dist/tshelper.js",
"line": 7,
"nonRuntime": false
}
},
{
"ruleId": "MTC-FLOW-005",
"title": "Untrusted input can drive an external action",
"category": "exfiltration",
"severity": "medium",
"confidence": "strong",
"description": "Untrusted-input tools ([tailscale_fetch, tailscale_connect_test, tailscale_check_messages]) co-exist with external-action tools ([tailscale_send_message]). 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": "tailscale_fetch → tailscale_send_message"
},
"evidence": "untrusted [tailscale_fetch, tailscale_connect_test, tailscale_check_messages] → sinks [tailscale_send_message]",
"owasp": "LLM06:2025 Excessive Agency",
"references": [],
"data": {
"untrusted": [
"tailscale_fetch",
"tailscale_connect_test",
"tailscale_check_messages"
],
"sinks": [
"tailscale_send_message"
]
}
},
{
"ruleId": "MTC-SUP-010",
"title": "Package runs install-time scripts (postinstall)",
"category": "supply-chain",
"severity": "low",
"confidence": "heuristic",
"description": "\"claude-code-tailscale\" 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": "claude-code-tailscale"
},
"evidence": "node scripts/postinstall.mjs",
"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"
]
}
}
],
"toxicFlows": [
{
"id": "flow-1",
"severity": "medium",
"confidence": "strong",
"untrustedInput": [
"tailscale_fetch",
"tailscale_connect_test",
"tailscale_check_messages"
],
"sensitiveSource": [],
"externalSink": [
"tailscale_send_message"
],
"selfContained": false,
"description": "Untrusted input can drive an external action even though no sensitive source is exposed."
}
],
"capabilities": [
{
"tool": "tailscale_status",
"tags": [],
"reasons": {}
},
{
"tool": "tailscale_fetch",
"tags": [
"untrusted-input"
],
"reasons": {
"untrusted-input": [
"keyword \"fetch\""
]
}
},
{
"tool": "tailscale_connect_test",
"tags": [
"untrusted-input"
],
"reasons": {
"untrusted-input": [
"keyword \"fetch\""
]
}
},
{
"tool": "tailscale_dns_lookup",
"tags": [],
"reasons": {}
},
{
"tool": "tailscale_whois",
"tags": [],
"reasons": {}
},
{
"tool": "tailscale_devices",
"tags": [],
"reasons": {}
},
{
"tool": "tailscale_ping",
"tags": [],
"reasons": {}
},
{
"tool": "tailscale_port_forward",
"tags": [],
"reasons": {}
},
{
"tool": "tailscale_acl_check",
"tags": [],
"reasons": {}
},
{
"tool": "tailscale_netcheck",
"tags": [],
"reasons": {}
},
{
"tool": "tailscale_cert",
"tags": [],
"reasons": {}
},
{
"tool": "tailscale_agents",
"tags": [],
"reasons": {}
},
{
"tool": "tailscale_send_message",
"tags": [
"external-sink"
],
"reasons": {
"external-sink": [
"keyword \"send_message\""
]
}
},
{
"tool": "tailscale_check_messages",
"tags": [
"untrusted-input"
],
"reasons": {
"untrusted-input": [
"keyword \"read_message\""
]
}
},
{
"tool": "tailscale_team_create",
"tags": [],
"reasons": {}
},
{
"tool": "tailscale_team_join",
"tags": [],
"reasons": {}
},
{
"tool": "tailscale_team_info",
"tags": [],
"reasons": {}
},
{
"tool": "tailscale_task_create",
"tags": [],
"reasons": {}
},
{
"tool": "tailscale_task_list",
"tags": [],
"reasons": {}
},
{
"tool": "tailscale_task_update",
"tags": [],
"reasons": {}
}
],
"surfaceDigest": "ac4d7d8e66f367233441f132e12525e93398169b8532e19b1fac418b0cb36f9f",
"stats": {
"tools": 20,
"prompts": 0,
"resources": 0,
"findingsBySeverity": {
"critical": 0,
"high": 1,
"medium": 1,
"low": 1,
"info": 0
}
}
}