Medium Risk

acme_update_certificate

Update certificate settings (renewal interval, restart actions, enable/disable, description)

How to control acme_update_certificate ↓

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

Medium Risk

The tool creates or modifies certificate configuration data reversibly. While updating certificate settings could affect system behavior (restart actions, renewal intervals), the changes are configuration-level modifications rather than code execution or destructive deletion.

From the tool's definition Tool name 'acme_update_certificate' and description explicitly states it updates certificate settings including 'renewal interval, restart actions, enable/disable, description'. This modifies configuration state.

Documented attack patterns abuse exactly the kind of access acme_update_certificate gives an agent:

PolicyLayer is an MCP gateway — it sits between your AI agents and OPNSense MCP Server, and nothing reaches the server without passing your rules. This is the rule we recommend for acme_update_certificate:

policy.json
{
  "version": "1",
  "default": "deny",
  "tools": {
    "acme_update_certificate": {
      "limits": [
        {
          "counter": "acme_update_certificate_rate",
          "window": "minute",
          "max": 30,
          "scope": "grant"
        }
      ]
    }
  }
}

acme_update_certificate 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.

  1. Create a free account and register OPNSense MCP Server — nothing to install.
  2. Add this policy — paste it, or build it visually.
  3. Point your MCP client (Claude, Cursor, anything) at your gateway URL.
LIMIT THIS TOOL →

Free to start. No card required.

Go deeper

What does the acme_update_certificate tool do? +

Update certificate settings (renewal interval, restart actions, enable/disable, description). It is categorised as a Write tool in the OPNSense MCP Server MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on acme_update_certificate? +

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

What risk level is acme_update_certificate? +

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

Can I rate-limit acme_update_certificate? +

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

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

acme_update_certificate is provided by the OPNSense MCP Server MCP server (vespo92/opnsensemcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.

Enforce policy on every OPNSense MCP Server tool call.

Deterministic rules across all 196 OPNSense MCP Server tools. Per-identity grants. Full audit log. Live in minutes. Nothing to install.

Free to start. No card required.

196 OPNSense MCP Server tools catalogued and risk-classified — across an index of 42,500+ MCP servers.

// GET IN TOUCH

Have a question or want to learn more? Send us a message.

Message sent.

We'll get back to you soon.