pfsense_update_user_group · Pfsense MCP: Risk & Policy

WHAT IT DOES

What pfsense_update_user_group does on Pfsense

AI agents use pfsense_update_user_group 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_update_user_group needs a policy

This tool modifies user group configurations on a critical network security appliance. While not irreversible (making it Write rather than Destructive) and not code execution (making it Write rather than Execute), misconfiguration of user groups could lock out legitimate administrators, grant unintended access, or disrupt authentication services.

From the tool's definition Tool name 'pfsense_update_user_group' indicates modification of user group configuration on a pfSense firewall.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

pfsense_update_user_group Rate-limited

pfsense_update_user_group 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_update_user_group": {
      "limits": [
        {
          "counter": "pfsense_update_user_group_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_update_user_group

What does the pfsense_update_user_group tool do? +

pfsense_update_user_group. 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_update_user_group? +

Register the Pfsense MCP server in PolicyLayer and add a rule for pfsense_update_user_group: 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_update_user_group? +

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

Can I rate-limit pfsense_update_user_group? +

Yes. Add a rate_limit block to the pfsense_update_user_group 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_update_user_group completely? +

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

pfsense_update_user_group 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.