nmap_os_detection · Nmap MCP Server MCP: Risk & Policy

WHAT IT DOES

What nmap_os_detection does on Nmap MCP Server

AI agents invoke nmap_os_detection to trigger actions in Nmap MCP Server. 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 nmap_os_detection needs a policy

OS detection scans actively send crafted packets to remote hosts to fingerprint their operating systems. This constitutes execution of an external network operation against potentially unauthorized targets. The blast radius is high because it can be used for reconnaissance against any reachable host, and OS fingerprinting is a common precursor to targeted attacks.

From the tool's definition 'Perform operating system detection scan' using Nmap, which actively probes remote hosts on a network

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

nmap_os_detection Rate-limited

nmap_os_detection 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": {
    "nmap_os_detection": {
      "limits": [
        {
          "counter": "nmap_os_detection_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 Nmap MCP Server, so you can run agents against it safely.

FAQ

Questions about nmap_os_detection

What does the nmap_os_detection tool do? +

Perform operating system detection scan. It is categorised as a Execute tool in the Nmap MCP Server MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.

How do I enforce a policy on nmap_os_detection? +

Register the Nmap MCP Server MCP server in PolicyLayer and add a rule for nmap_os_detection: 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 Nmap MCP Server. Nothing to install.

What risk level is nmap_os_detection? +

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

Can I rate-limit nmap_os_detection? +

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

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

nmap_os_detection is provided by the Nmap MCP Server MCP server (mohdhaji87/nmap-mcp-server). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.