fuzz_dirs · Hercules MCP: Risk & Policy

WHAT IT DOES

What fuzz_dirs does on Hercules MCP

AI agents invoke fuzz_dirs to trigger actions in Hercules MCP. What it does depends on the arguments the agent supplies, and its effects often reach beyond the immediate call — builds kicked off, notifications sent, workflows started.

WHY IT NEEDS A POLICY

Why fuzz_dirs needs a policy

Directory brute-forcing is an active reconnaissance operation that executes external tools to probe target systems. While it does not directly delete or modify data (ruling out Destructive), it actively executes commands against external systems whose effects depend on the target argument. This makes it Execute category.

From the tool's definition Tool performs directory brute-forcing using industry-standard offensive security tools (gobuster/ffuf) as explicitly stated in the description. The server itself is described as enabling 'penetration testing' with 'offensive security tools'.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

fuzz_dirs Rate-limited

fuzz_dirs stays usable, but rate-capped — a runaway agent can't fire it dozens of times a minute. Everything else on the server is denied unless you say otherwise.

View as policy code

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "fuzz_dirs": {
      "limits": [
        {
          "counter": "fuzz_dirs_rate",
          "window": "minute",
          "max": 10,
          "scope": "grant"
        }
      ]
    }
  }
}

RATE-LIMIT THIS TOOL →

Instant setup, no code required.

PolicyLayer is an MCP gateway: every tool call is checked against your rule before it reaches Hercules MCP, so you can run agents against it safely.

FAQ

Questions about fuzz_dirs

What does the fuzz_dirs tool do? +

Directory brute-forcing (gobuster/ffuf). It is categorised as a Execute tool in the Hercules MCP MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.

How do I enforce a policy on fuzz_dirs? +

Register the Hercules MCP server in PolicyLayer and add a rule for fuzz_dirs: allow, deny, rate-limit, or require approval. Point your MCP client at the PolicyLayer proxy URL and the rule is enforced on every call, before it reaches Hercules MCP. Nothing to install.

What risk level is fuzz_dirs? +

fuzz_dirs is a Execute tool with high risk. Execute tools should be rate-limited and have argument validation enabled.

Can I rate-limit fuzz_dirs? +

Yes. Add a rate_limit block to the fuzz_dirs rule in your PolicyLayer policy. For example, setting max: 10 and window: 60 limits the tool to 10 calls per minute. Rate limits are tracked per agent session and reset automatically.

How do I block fuzz_dirs completely? +

Set action: deny in the PolicyLayer policy for fuzz_dirs. The AI agent will receive a policy violation error and cannot call the tool. You can also include a reason field to explain why the tool is blocked.

What MCP server provides fuzz_dirs? +

fuzz_dirs is provided by the Hercules MCP server (0xmihirk/hercules-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.