pfsense_create_system_tunable · Pfsense MCP: Risk & Policy

WHAT IT DOES

What pfsense_create_system_tunable does on Pfsense

AI agents use pfsense_create_system_tunable to create or update resources in Pfsense — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your Pfsense environment.

WHY IT NEEDS A POLICY

Why pfsense_create_system_tunable needs a policy

This tool creates or modifies system tunable parameters on a firewall. While it does not permanently delete data (which would be Destructive), and does not transfer funds (Financial), it does modify system configuration that could impact firewall performance and behavior. The high severity reflects that misuse could degrade firewall functionality, potentially affecting network security posture.

From the tool's definition Tool name contains 'create' and description indicates POST request to /api/v2/system/tunable, which creates or modifies system tuning parameters on a pfSense firewall. POST operations that modify system configuration are Write operations.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

pfsense_create_system_tunable Rate-limited

pfsense_create_system_tunable stays usable, but capped — an agent stuck in a loop can't make hundreds of changes a minute. Everything else on the server is denied unless you say otherwise.

View as policy code

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "pfsense_create_system_tunable": {
      "limits": [
        {
          "counter": "pfsense_create_system_tunable_rate",
          "window": "minute",
          "max": 30,
          "scope": "grant"
        }
      ]
    }
  }
}

LIMIT THIS TOOL →

Instant setup, no code required.

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

FAQ

Questions about pfsense_create_system_tunable

What does the pfsense_create_system_tunable tool do? +

POST /api/v2/system/tunable. It is categorised as a Write tool in the Pfsense MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on pfsense_create_system_tunable? +

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

What risk level is pfsense_create_system_tunable? +

pfsense_create_system_tunable is a Write tool with medium risk. Write tools should be rate-limited to prevent accidental bulk modifications.

Can I rate-limit pfsense_create_system_tunable? +

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

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

pfsense_create_system_tunable is provided by the Pfsense MCP server (abl030/pfsense-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.