io.github.j7an/nexus-mcp

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/nexus_mcp/config_resolver.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

  fail15% of grade

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

  HIGH: shell/exec capability AND network egress together — download-and-execute risk (src/nexus_mcp/cli_detector.py: subprocess.* call; pyproject declares an HTTP client dependency). HIGH: shell/exec capability AND destructive filesystem writes together (src/nexus_mcp/cli_detector.py: subprocess.* call; tests/fixtures.py: path traversal ('../') combined with file access). discloses shell/exec capability: src/nexus_mcp/cli_detector.py: subprocess.* call discloses shell/exec capability: tests/integration/test_cli_detection.py: subprocess.* call discloses dynamic code execution: tests/unit/test___main__.py: uses eval/exec/__import__ discloses broad/destructive filesystem access: tests/fixtures.py: path traversal ('../') combined with file access discloses broad/destructive filesystem access: tests/unit/runners/test_opencode.py: path traversal ('../') combined with file access Capability DISCLOSURE, not a verdict: static analysis sees the primitive is present and reachable, not whether its use is attacker-controlled.

• Version behavior

  unscannable10% of grade

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

  no prior version to diff (first sight of io.github.j7an/[email protected]); version-drift / rug-pull cannot be evaluated. Cold-start risk is covered by point-in-time checks (injection_surface, supply_chain, credential_hygiene), not here.

• Transport config

  warn10% of grade

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

  manifest/source references tracking behavior — disclosure