io.github.atomno-labs/mcp-fns-check v0.1.2
Host io.github.atomno-labs/mcp-fns-check in a governed environment — SSO in front, every tool call attributed and audited.
Security controls
Deterministic, evidence-backed. Score earned from passing controls; a failed guard caps it.
Security controls
Deterministic, evidence-backed. Score earned from passing controls; a failed guard caps it.
Model–MCP Runtime Guardrails
- WarnStrict JSON Schema Enforcementschemas not strict
Tool inputs are constrained (additionalProperties:false), so unexpected arguments can't be smuggled in.
Fix: Set additionalProperties:false and require explicit parameters on every tool.
- PassIndirect Prompt Injection (IPI) Defensesguardno injection markers
Tool/prompt/resource text is free of hidden instructions that could hijack the agent.
- PassUser-in-the-Loop / Approval Scopeguardno destructive tool scope
No over-broad or destructive tools (arbitrary shell, bulk-delete) that warrant human approval.
- N/ATool Definition Stabilityguardno prior version to diff
Tool definitions did not change after publish — no post-approval rug-pull.
Application Security Checks
- WarnDependencies pinned (lockfile)no lockfile found
A lockfile makes installs reproducible and resistant to silent dependency swaps.
Fix: Commit a lockfile (package-lock.json / pnpm-lock.yaml / poetry.lock).
- WarnEstablished maintainerrecently published
Brand-new / single anonymous maintainers raise takeover and malware risk.
Fix: Publish under an established account/org; add multiple maintainers.
- WarnHas a security policyno security policy
A SECURITY.md gives a private path to report vulnerabilities.
Fix: Add SECURITY.md with a disclosure contact and process.
- WarnAdoption & popularitylimited adoption
A small, capped nudge from stars/downloads — widely-used servers get more eyes on bugs. It can never offset a real security failure.
Fix: Adoption grows naturally with real-world use; this never gates the score.
- PassNo command-injection sinksguardno sinks found
Untrusted tool input reaching a shell yields remote code execution.
- PassNo dynamic code executionguardno sinks found
eval()/exec()/Function() on tool-derived strings allows arbitrary code execution.
- PassNo path traversalguardno sinks found
Naive path checks let tools read/write outside intended directories (EscapeRoute-class).
- PassNo SSRF sinksguardno sinks found
Fetching tool-supplied URLs can pivot into internal networks and metadata services.
- PassNo unsafe deserializationguardno sinks found
pickle/yaml.load/etc. on untrusted data can execute code.
- PassNo committed secretsguardno secrets found
Hardcoded keys/tokens in published source are live credentials an attacker can use.
- PassCredentials sourced from environmentreads credentials from environment
Reading secrets from env/secret stores avoids hardcoding them.
- PassNo known-vulnerable dependencies1 runtime deps, no known CVEs
Runtime dependencies (parsed from the lockfile) are scanned against OSV.dev for published CVEs. Advisory: flagged dependencies lower the score but don't hard-cap it, since transitive reachability is unproven.
- PassPackage name not typosquattingguarddistinct package name
Names mimicking popular packages are a common malware delivery vector.
- PassActively maintainedrecent commits
Unmaintained servers don't receive security fixes.
- PassRepository not archivedguardactive
Archived repositories will never be patched.
- PassDeclares a licenseMIT
A clear license is required for legal enterprise use.
- Not checkedNo install/post-install scriptsguardnot determinable from PyPI metadata
install hooks run arbitrary code on every consumer at install time.
- Not checkedPublished with provenancenot determinable
Build provenance attests the artifact was built from the claimed source by CI.
- Not checkedSigned releasesnot evaluated
Signed releases let consumers verify artifacts weren't tampered with.
Transport & Trust Model
- WarnExecution Sandboxingruns natively (no container image)
A container/sandbox image limits blast radius; a server that runs natively has full host access.
Fix: Ship a Dockerfile/Containerfile (or document a sandboxed run) so the server runs isolated.
- PassNetwork Exposureno bind-all detected
Binding 0.0.0.0 or exposing debug inspectors widens the attack surface.
- N/ATransport Encryption (TLS)guardno remote endpoints
Plaintext HTTP exposes traffic and bearer tokens to interception.
- N/AIAM / Authentication Scopingno remote endpoints
OAuth 2.1 / Protected Resource Metadata gates who can invoke tools.
- N/ALive Endpoint Reachablenot dynamically scanned
A dynamic scan connected to the declared remote endpoint and it responded — verified live, not a dead URL.
- N/AAuthentication Enforced (live)not dynamically scanned
If the server declares auth is required, it must actually reject anonymous clients. Serving tools to unauthenticated callers is a real exposure.