os_detection

Perform OS detection on the specified target with optional custom arguments.

SERVERNmapMCP SOURCE0xpratikpatil/nmapmcp

High RISK CLASS

Category Execute

Parameters 00 required

Recommended Rate-limitedsee the rule below

Registry record Grade F, identity unverified Pull the record →

This record as markdown: /tools/0xpratikpatil-nmapmcp/os-detection.md

WHAT IT DOES

What os_detection does on NmapMCP

AI agents invoke os_detection to trigger actions in NmapMCP. 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.

RISK

Why os_detection is rated High

OS detection involves sending crafted network packets to an external target to fingerprint its operating system. This is an active network reconnaissance operation with real-world side effects on external systems. It falls under Execute (triggering external operations) rather than Read, as it actively interacts with remote infrastructure.

From the tool's definition 'Perform OS detection on the specified target' — actively probes a remote host to fingerprint its operating system

Attacks that exploit this kind of access

RECOMMENDED RULE

The rule that runs os_detection safely

PolicyLayer is an MCP gateway: it sits between your AI agents and NmapMCP, and checks every tool call against a rule you set before the call runs. Nothing changes on the server itself. For os_detection, this is the rule to start with:

os_detection Rate-limited

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": {
    "os_detection": {
      "limits": [
        {
          "counter": "os_detection_rate",
          "window": "minute",
          "max": 10,
          "scope": "grant"
        }
      ]
    }
  }
}

RATE-LIMIT THIS TOOL → Instant setup, no code required.

The button opens the PolicyLayer dashboard: create your workspace, connect NmapMCP, apply this rule, and every os_detection call is checked against it from then on.

FAQ

Questions about os_detection

What does the os_detection tool do? +

Perform OS detection on the specified target with optional custom arguments. It is categorised as a Execute tool in the NmapMCP MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.

How do I enforce a policy on os_detection? +

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

What risk level is os_detection? +

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

Can I rate-limit os_detection? +

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

Set action: deny in the PolicyLayer policy for 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 os_detection? +

os_detection is provided by the Nmap MCP server (0xpratikpatil/nmapmcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.

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