Audit MCP

audit-mcp — MCP Server Security Audit

Walk every server declared in ~/.hermes/config.yaml under mcp_servers: and produce a structured report with risk flags.

Hermes has no per-server trust: levels or allow_sampling: knobs — the real controls are tool filtering (tools.include / tools.exclude), credential scoping (what you pass via env:), and operator review before install (Part 19, Layer 5). This audit checks exactly those.

Procedure

1. Read the config. Load ~/.hermes/config.yaml and extract the mcp_servers: block. If the block is empty or missing, report "No MCP servers configured" and exit.

2. For each server, collect:

   • Server name and transport (stdio if command: present, http if url: present)
   • enabled: flag and timeout:
   • tools.include / tools.exclude — present? how many tools locked in vs exposed?
   • env: entries — which credentials this server receives
   • Source identifier: npm package (parse from args:), git URL, or HTTP origin
   • Last-updated timestamp:
     • npm: npm view <pkg> time.modified
     • git: git -C <path> log -1 --format=%cI
     • http: attempt a HEAD and grab Last-Modified

3. Risk-flag each server:

   • 🔴 HIGH: server ingests untrusted content (web scraping, email parsing, public RSS — tool names matching /scrape|fetch|email|rss|crawl/i) AND has an empty tools.include (= all tools exposed) or write-capable tools included.
   • 🔴 HIGH: env: passes a broad credential (e.g. an unscoped GITHUB_PERSONAL_ACCESS_TOKEN) to a server that reads attacker-influenced text (the Comment-and-Control pattern).
   • 🟡 MEDIUM: last updated > 90 days ago.
   • 🟡 MEDIUM: empty tools.include on a server with > 10 tools exposed.
   • 🟡 MEDIUM: referenced ${VAR} in env: is not set in ~/.hermes/.env (check key names only — never read values).
   • 🟢 LOW: enabled: true on a server the logs show unused for 30+ days — dead attack surface.

4. Render a table. Columns: name, transport, enabled, tools-included / tools-exposed, credentials passed, last-update age, flags.

5. Summarize next steps. Group findings by flag color and recommend:

   • HIGH: "Set tools.include: to the specific read-only tools you audited; swap the credential for a scoped read-only one."
   • MEDIUM stale: "Run npm update <pkg> or rebuild the git source; verify release notes."
   • MEDIUM missing include list: "Add tools.include: with the specific tools you actually use."
   • For servers that ingest untrusted content: "Run under whole-process isolation, or launch the server inside a sandbox — see Part 21."

6. Offer to apply fixes. Ask the user if they'd like to:

   • Write a suggested tools.include: based on hermes logs usage history
   • Disable (enabled: false) servers unused for 30+ days
   • Downscope any credential in env: flagged as broad

Never auto-apply without confirmation.

Output format

Report as markdown. Paste into Telegram / Discord / dashboard as-is. Example:

## MCP Security Audit — 2026-06-17

### 🔴 HIGH (1)
- **random-scraper** — reads untrusted content with empty tools.include (`scrape_url`, `fetch_rss`, 12 more exposed)

### 🟡 MEDIUM (2)
- **postgres** — last updated 127 days ago (package @modelcontextprotocol/server-postgres)
- **github** — empty tools.include, 34 tools exposed

### 🟢 LOW (1)
- **filesystem** — enabled but no tool calls in 30 days

### Recommendations
1. Lock `random-scraper` to `tools.include: [read_docs]` and run it inside a sandbox.
2. `npm update @modelcontextprotocol/server-postgres`.
3. Scope `github` to the 6 tools actually used in last 30d.

Notes

• Runs entirely locally. No data leaves the host.
• Pair with a weekly cron job (see Part 19; create it with hermes cron create "0 9 * * 1" ... --skill audit-mcp) — this skill is read-only, so approvals.cron_mode: deny won't block it.
• Uses terminal to exec npm view / git log; uses file to read the config.