Critical Risk →

firewall_delete_rule

Delete a firewall rule

How to control firewall_delete_rule ↓

AI agents call firewall_delete_rule to permanently remove resources in OPNSense MCP Server — typically in cleanup and lifecycle workflows. It does its job in a single call, and there is no undo.

Critical Risk

Firewall rule deletion is inherently destructive—it cannot be undone without manual recreation and removes security controls. The blast radius is high as incorrect deletion could expose systems to unauthorized access or disrupt network security policies.

From the tool's definition Tool name contains 'delete' and description states 'Delete a firewall rule'. The operation irreversibly removes firewall rules that protect network infrastructure.

Documented attack patterns abuse exactly the kind of access firewall_delete_rule 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 firewall_delete_rule:

policy.json
{
  "version": "1",
  "default": "deny",
  "hide": [
    "firewall_delete_rule"
  ]
}

firewall_delete_rule disappears from the agent's tool list entirely, and any attempt to call it is denied. The rest of the server keeps working.

  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.
RESTRICT THIS TOOL →

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Go deeper

What does the firewall_delete_rule tool do? +

Delete a firewall rule. It is categorised as a Destructive tool in the OPNSense MCP Server MCP Server, which means it can permanently delete or destroy data. Block by default and require explicit approval.

How do I enforce a policy on firewall_delete_rule? +

Register the OPNSense MCP Server MCP server in PolicyLayer and add a rule for firewall_delete_rule: 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 firewall_delete_rule? +

firewall_delete_rule is a Destructive tool with critical risk. Critical-risk tools should be blocked by default and only enabled with explicit human approval.

Can I rate-limit firewall_delete_rule? +

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

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

firewall_delete_rule 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.

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