Zen — 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": "zen-mcp",
"source": {
"kind": "package",
"origin": "zen-mcp"
},
"server": {
"name": "zen-mcp"
}
},
"grade": "A",
"score": {
"score": 93,
"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": "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-1.13"
},
"capability": {
"level": "high",
"reasons": [
"ingests untrusted external content (a prompt-injection entry point)",
"can execute shell commands or code"
],
"tags": [
"code-exec",
"untrusted-input"
]
},
"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-CAP-001",
"title": "Tool \"zen_evaluate\" exposes command/code execution",
"category": "permissions",
"severity": "high",
"confidence": "strong",
"description": "Tool \"zen_evaluate\" appears to run shell commands or evaluate code (parameter \"script\"). Arbitrary execution driven by model input is one of the most dangerous MCP capabilities; combined with any untrusted input it becomes RCE.",
"remediation": "Sandbox execution, allowlist commands/arguments, and never pass model output to a shell unescaped.",
"location": {
"kind": "tool",
"name": "zen_evaluate"
},
"owasp": "LLM05:2025 Improper Output Handling",
"data": {
"tags": [
"code-exec"
]
}
},
{
"ruleId": "MTC-FLOW-005",
"title": "Untrusted input can drive an external action",
"category": "exfiltration",
"severity": "medium",
"confidence": "strong",
"description": "Untrusted-input tools ([zen_get_page_text]) co-exist with external-action tools ([zen_evaluate]). 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": "zen_get_page_text → zen_evaluate"
},
"evidence": "untrusted [zen_get_page_text] → sinks [zen_evaluate]",
"owasp": "LLM06:2025 Excessive Agency",
"references": [],
"data": {
"untrusted": [
"zen_get_page_text"
],
"sinks": [
"zen_evaluate"
]
}
},
{
"ruleId": "MTC-CAP-006",
"title": "Unconstrained command parameter \"script\" on \"zen_evaluate\"",
"category": "permissions",
"severity": "medium",
"confidence": "heuristic",
"description": "Tool \"zen_evaluate\" takes a command-shaped parameter \"script\" with no enum/pattern constraint. Free-form, model- or attacker-controlled arguments reaching a shell is the command-injection precondition.",
"remediation": "Constrain the parameter (enum/pattern), or build the command from a fixed template with escaped args.",
"location": {
"kind": "tool",
"name": "zen_evaluate",
"field": "inputSchema.properties.script"
},
"owasp": "LLM05:2025 Improper Output Handling",
"data": {
"param": "script"
}
},
{
"ruleId": "MTC-CAP-005",
"title": "Mutating tool \"zen_evaluate\" declares no destructiveHint",
"category": "hygiene",
"severity": "low",
"confidence": "heuristic",
"description": "Tool \"zen_evaluate\" can mutate/egress but declares no destructiveHint. Clients that don't default to spec-safe behavior may not prompt before running it.",
"remediation": "Declare accurate annotations, and gate destructive tools on user confirmation regardless.",
"location": {
"kind": "tool",
"name": "zen_evaluate"
},
"data": {
"tags": [
"code-exec"
]
}
}
],
"toxicFlows": [
{
"id": "flow-1",
"severity": "medium",
"confidence": "strong",
"untrustedInput": [
"zen_get_page_text"
],
"sensitiveSource": [],
"externalSink": [
"zen_evaluate"
],
"selfContained": false,
"description": "Untrusted input can drive an external action even though no sensitive source is exposed."
}
],
"capabilities": [
{
"tool": "zen_list_pages",
"tags": [],
"reasons": {}
},
{
"tool": "zen_select_page",
"tags": [],
"reasons": {}
},
{
"tool": "zen_new_tab",
"tags": [],
"reasons": {}
},
{
"tool": "zen_navigate",
"tags": [],
"reasons": {}
},
{
"tool": "zen_snapshot",
"tags": [],
"reasons": {}
},
{
"tool": "zen_screenshot",
"tags": [],
"reasons": {}
},
{
"tool": "zen_click",
"tags": [],
"reasons": {}
},
{
"tool": "zen_fill",
"tags": [],
"reasons": {}
},
{
"tool": "zen_select_option",
"tags": [],
"reasons": {}
},
{
"tool": "zen_check",
"tags": [],
"reasons": {}
},
{
"tool": "zen_evaluate",
"tags": [
"code-exec"
],
"reasons": {
"code-exec": [
"parameter \"script\""
]
}
},
{
"tool": "zen_get_form_fields",
"tags": [],
"reasons": {}
},
{
"tool": "zen_fill_form",
"tags": [],
"reasons": {}
},
{
"tool": "zen_scroll",
"tags": [],
"reasons": {}
},
{
"tool": "zen_wait",
"tags": [],
"reasons": {}
},
{
"tool": "zen_get_page_text",
"tags": [
"untrusted-input"
],
"reasons": {
"untrusted-input": [
"keyword \"get_page\""
]
}
},
{
"tool": "zen_close_tab",
"tags": [],
"reasons": {}
},
{
"tool": "zen_press_key",
"tags": [],
"reasons": {}
},
{
"tool": "zen_reconnect",
"tags": [],
"reasons": {}
},
{
"tool": "zen_wait_for",
"tags": [],
"reasons": {}
}
],
"surfaceDigest": "5bca6c57b3d0691e7aefde390b16c7ab93bbd4cb622dc034c94bcfa84f6a3464",
"stats": {
"tools": 20,
"prompts": 0,
"resources": 0,
"findingsBySeverity": {
"critical": 0,
"high": 1,
"medium": 2,
"low": 1,
"info": 0
}
}
}