io.github.cmendezs/mcp-einvoicing-core

What we checked

Six static checks, weighted by risk. Every result reflects only what could be observed in the published package and repository — never intent.

• Injection surface

  unscannable25% of grade

  Tool descriptions/manifest scanned for instruction-injection patterns (imperatives at the model, hidden text, 'ignore previous', data-exfil URLs).

  No tool descriptions, server instructions, prompts, or resources were fetched; nothing to scan for injection.

• Supply chain

  fail25% of grade

  Package provenance: namespace verification, repo linkage, maintainer count, account age, postinstall scripts, typosquat distance.

  Python build script executes at build time: network call in build script

• Credential hygiene

  pass15% of grade

  How the server takes secrets (env vs plaintext config vs hardcoded); secrets appearing in tool schemas.

  Reads secrets from the environment (e.g. src/mcp_einvoicing_core/audit_log.py) — the recommended intake shape. PASS = no static red flag; static analysis cannot prove the code honors env-based secret handling at runtime.

• Permission scope

  warn15% of grade

  Declared tools vs. breadth (filesystem, network, exec); flags shell-exec and unbounded filesystem access.

  has both shell/exec and network egress — capable of download-and-run, though no such path was observed (pyproject declares an exec-oriented dependency (pexpect/fabric/invoke); src/mcp_einvoicing_core/download_rules.py: outbound HTTP/socket call). has both shell/exec and destructive filesystem writes (pyproject declares an exec-oriented dependency (pexpect/fabric/invoke); src/mcp_einvoicing_core/http_client.py: open(…, 'w'/'a'/'x') write-mode file access). discloses shell/exec capability: pyproject declares an exec-oriented dependency (pexpect/fabric/invoke) discloses broad/destructive filesystem access: src/mcp_einvoicing_core/http_client.py: open(…, 'w'/'a'/'x') write-mode file access discloses broad/destructive filesystem access: src/mcp_einvoicing_core/http_client.py: destructive filesystem call (shutil.rmtree/os.remove/etc.) discloses broad/destructive filesystem access: src/mcp_einvoicing_core/signer_service.py: destructive filesystem call (shutil.rmtree/os.remove/etc.) Capability DISCLOSURE, not a verdict: static analysis sees the primitive is present and reachable, not whether its use is attacker-controlled.

• Version behavior

  fail10% of grade

  Diff of tool definitions between versions; new permissions or changed descriptions in a patch release (the postmark-mcp class).

  vs prior 1.28.1 (minor bump): new capability primitive(s) in source: fs-write, http-client; new hardcoded outbound host/BCC destination(s): ..., api.example.com, busdox.org, cloudflare-dns.com, directory.peppol.eu, docs.oasis-open.org, docs.peppol.eu, ec.europa.eu, finances.belgium.be, github.com, ivaservizi.agenziaentrate.gov.it, purl.oclc.org, test-directory.peppol.eu, test.example.com, uri.etsi.org, www.agenciatributaria.es, www.aiim.org, www.bzst.de, www.facturae.es, www.gov.pl, www.iana.org, www.insee.fr, www.sat.gob.mx, www.unece.org, www.w3.org, www.xoev.de.

• Transport config

  unscannable10% of grade

  Remote servers: TLS and auth mode (none/token/OAuth). Local servers: whether the manifest indicates it phones home.

  local stdio server: no remote transport or auth surface, and no phone-home/telemetry signal found in source. Absence of transport findings is NOT a safety guarantee — phone-home hosts can be constructed at runtime and defeat static analysis.