subfinder_scan · Kali MCP: Risk & Policy

WHAT IT DOES

What subfinder_scan does on Kali

AI agents invoke subfinder_scan to trigger actions in Kali. 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 subfinder_scan needs a policy

subfinder is a subdomain enumeration tool that actively queries DNS, third-party APIs, and other sources to discover subdomains of a target. It performs external reconnaissance operations whose effects depend on the provided target parameters.

From the tool's definition Execute subfinder with the provided parameters — runs an active subdomain discovery tool on a target domain as part of a Kali Linux penetration testing server supporting 'network scanning, web scanning, password attacks'

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

subfinder_scan Rate-limited

subfinder_scan 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": {
    "subfinder_scan": {
      "limits": [
        {
          "counter": "subfinder_scan_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 Kali, so you can run agents against it safely.

FAQ

Questions about subfinder_scan

What does the subfinder_scan tool do? +

Execute subfinder with the provided parameters. It is categorised as a Execute tool in the Kali MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.

How do I enforce a policy on subfinder_scan? +

Register the Kali MCP server in PolicyLayer and add a rule for subfinder_scan: 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 Kali. Nothing to install.

What risk level is subfinder_scan? +

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

Can I rate-limit subfinder_scan? +

Yes. Add a rate_limit block to the subfinder_scan 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 subfinder_scan completely? +

Set action: deny in the PolicyLayer policy for subfinder_scan. 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 subfinder_scan? +

subfinder_scan is provided by the Kali MCP server (pentestt00ls/kali-mcp-server). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.