Sftp — 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": "@cordfuse/sftp-mcp",
"source": {
"kind": "package",
"origin": "@cordfuse/sftp-mcp"
},
"server": {
"name": "@cordfuse/sftp-mcp"
}
},
"grade": "A",
"score": {
"score": 91,
"threatScore": 99,
"grade": "A",
"band": "A",
"categorySubtotals": {
"injection": 1.2,
"exfiltration": 0,
"permissions": 0,
"supply-chain": 0,
"network": 0,
"hygiene": 0
},
"vector": [
{
"kind": "threat",
"ruleId": "MTC-INJ-CMD-1",
"category": "injection",
"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 create, modify or delete files",
"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": [
"sensitive-source",
"untrusted-input",
"external-sink",
"file-write"
]
},
"coverage": {
"level": "source",
"inputs": {
"toolSurface": true,
"implementationSource": true,
"packageMetadata": true,
"liveTransport": false
},
"caveats": [
"Tools were statically extracted from the published source (17 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: download_file → list_files → upload_file. Untrusted input is ingested, private data is read, and it can be sent to an external sink via the agent composing the tools (→). 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": "download_file → list_files → upload_file"
},
"owasp": "LLM02:2025 Sensitive Information Disclosure",
"references": [],
"data": {
"untrusted": [
"download_file",
"download_files"
],
"sources": [
"list_files"
],
"sinks": [
"upload_file"
],
"path": [
"download_file",
"list_files",
"upload_file"
],
"edges": [
{
"from": "download_file",
"to": "list_files",
"kind": "agent-mediated"
},
{
"from": "list_files",
"to": "upload_file",
"kind": "agent-mediated"
}
],
"wired": false
}
},
{
"ruleId": "MTC-SRC-006",
"title": "Reads a sensitive credential path or dumps the environment (dist/sftp.js)",
"category": "exfiltration",
"severity": "high",
"confidence": "strong",
"description": "In the server's implementation (`dist/sftp.js:8`): Reading private keys / cloud credentials, or serializing the whole environment, is a sensitive-data source that becomes exfiltration when combined with any egress. 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/sftp.js"
},
"evidence": "const DEFAULT_KEYS = [\"id_ed25519\", \"id_ecdsa\", \"id_rsa\"]; /** * Resolve authentication for a connection. Priority: in",
"owasp": "LLM02:2025 Sensitive Information Disclosure",
"data": {
"rule": "MTC-SRC-006",
"file": "dist/sftp.js",
"line": 8,
"nonRuntime": false
}
},
{
"ruleId": "MTC-CAP-002",
"title": "Tool \"delete_file\" can modify the filesystem",
"category": "permissions",
"severity": "medium",
"confidence": "strong",
"description": "Tool \"delete_file\" can write, overwrite or delete files (keyword \"delete_file\" in tool name). Verify it is scoped to a safe directory.",
"remediation": "Constrain file operations to an explicit, non-sensitive root; reject path traversal.",
"location": {
"kind": "tool",
"name": "delete_file"
},
"data": {
"tags": [
"file-write"
]
}
},
{
"ruleId": "MTC-CAP-005",
"title": "Mutating tool \"delete_file\" declares no destructiveHint",
"category": "hygiene",
"severity": "low",
"confidence": "heuristic",
"description": "Tool \"delete_file\" 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": "delete_file"
},
"data": {
"tags": [
"file-write"
]
}
},
{
"ruleId": "MTC-INJ-CMD-1",
"title": "Shell command embedded in tool metadata",
"category": "injection",
"severity": "low",
"confidence": "heuristic",
"description": "Shell command embedded in tool metadata detected in the description of tool \"delete_dir\". Instruction-like content in tool metadata is executed by the model, not the human, and is the primary tool-poisoning vector.",
"remediation": "Tool descriptions should describe behavior, not instruct the assistant. Treat imperative / secrecy / sequencing language in metadata as hostile.",
"location": {
"kind": "tool",
"name": "delete_dir",
"field": "description"
},
"evidence": "rm -rf",
"owasp": "LLM01:2025 Prompt Injection",
"data": {
"kind": "command-in-prose"
}
},
{
"ruleId": "MTC-CAP-008",
"title": "Unconstrained path parameter \"path\" on \"list_files\"",
"category": "permissions",
"severity": "low",
"confidence": "heuristic",
"description": "Tool \"list_files\" takes a path parameter \"path\" with no constraint. Without a canonicalize-and-contain check (not visible statically), this permits ../ traversal outside the intended root.",
"remediation": "Resolve and verify the path stays within an allowed root; reject traversal sequences.",
"location": {
"kind": "tool",
"name": "list_files",
"field": "inputSchema.properties.path"
},
"data": {
"param": "path"
}
},
{
"ruleId": "MTC-CAP-008",
"title": "Unconstrained path parameter \"path\" on \"delete_file\"",
"category": "permissions",
"severity": "low",
"confidence": "heuristic",
"description": "Tool \"delete_file\" takes a path parameter \"path\" with no constraint. Without a canonicalize-and-contain check (not visible statically), this permits ../ traversal outside the intended root.",
"remediation": "Resolve and verify the path stays within an allowed root; reject traversal sequences.",
"location": {
"kind": "tool",
"name": "delete_file",
"field": "inputSchema.properties.path"
},
"data": {
"param": "path"
}
},
{
"ruleId": "MTC-SUP-011",
"title": "Package declares no source repository",
"category": "supply-chain",
"severity": "info",
"confidence": "strong",
"description": "\"@cordfuse/sftp-mcp\" 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": "@cordfuse/sftp-mcp"
}
}
],
"toxicFlows": [
{
"id": "flow-1",
"severity": "critical",
"confidence": "strong",
"untrustedInput": [
"download_file",
"download_files"
],
"sensitiveSource": [
"list_files"
],
"externalSink": [
"upload_file"
],
"selfContained": false,
"path": [
"download_file",
"list_files",
"upload_file"
],
"pathWired": false,
"description": "A cross-tool exfiltration chain exists: download_file → list_files → upload_file."
}
],
"capabilities": [
{
"tool": "test_connection",
"tags": [],
"reasons": {}
},
{
"tool": "list_files",
"tags": [
"sensitive-source"
],
"reasons": {
"sensitive-source": [
"keyword \"list_files\""
]
}
},
{
"tool": "stat",
"tags": [],
"reasons": {}
},
{
"tool": "lstat",
"tags": [],
"reasons": {}
},
{
"tool": "realpath",
"tags": [],
"reasons": {}
},
{
"tool": "read_symlink",
"tags": [],
"reasons": {}
},
{
"tool": "disk_usage",
"tags": [],
"reasons": {}
},
{
"tool": "download_file",
"tags": [
"untrusted-input"
],
"reasons": {
"untrusted-input": [
"keyword \"download\""
]
}
},
{
"tool": "download_files",
"tags": [
"untrusted-input"
],
"reasons": {
"untrusted-input": [
"keyword \"download\""
]
}
},
{
"tool": "make_directory",
"tags": [],
"reasons": {}
},
{
"tool": "upload_file",
"tags": [
"external-sink"
],
"reasons": {
"external-sink": [
"keyword \"upload_file\""
]
}
},
{
"tool": "upload_dir",
"tags": [],
"reasons": {}
},
{
"tool": "delete_file",
"tags": [
"file-write"
],
"reasons": {
"file-write": [
"keyword \"delete_file\" in tool name"
]
}
},
{
"tool": "delete_dir",
"tags": [],
"reasons": {}
},
{
"tool": "move",
"tags": [],
"reasons": {}
},
{
"tool": "chmod",
"tags": [],
"reasons": {}
},
{
"tool": "symlink",
"tags": [],
"reasons": {}
}
],
"surfaceDigest": "bbefe8b6532b724ccd2b5e1e2dd44fea612a50ada2e1408d825349fea48cdb2d",
"stats": {
"tools": 17,
"prompts": 0,
"resources": 0,
"findingsBySeverity": {
"critical": 1,
"high": 1,
"medium": 1,
"low": 4,
"info": 1
}
}
}