system_shutdown

THE RISK

Critical Risk

Why system_shutdown needs a policy

Shutting down the system is an irreversible action in the sense that it cannot be undone remotely — it requires physical or out-of-band (IPMI) access to restart. This has maximum blast radius: all services, storage access, and operations are immediately halted, potentially causing data loss and significant downtime.

From the tool's definition 'Shut down the TrueNAS system. This is a DESTRUCTIVE operation — the system will power off and require physical or IPMI intervention to restart.'

Risk signalsAdmin/system-level operation

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

POLICY

How to control system_shutdown

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

policy.json

{
  "version": "1",
  "default": "deny",
  "hide": [
    "system_shutdown"
  ]
}

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

Create a free account and register Truenas — nothing to install.
Add this policy — paste it, or build it visually.
Point your MCP client (Claude, Cursor, anything) at your gateway URL.

RESTRICT THIS TOOL →

Free to start. No card required.

EXPLORE

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All 279 Truenas tools →

Destructive tools on other servers

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Go deeper

Critical-risk tools in Truenas → Every critical-risk tool this server exposes, in one view.
All critical-risk MCP tools → Every critical-risk tool across the catalogue, and the policy pattern that contains them.
The MCP Attack Database → Documented attack patterns against MCP deployments — and the policies that stop them.
Blast radius → How much damage one compromised or confused agent can do — and how to bound it.
Tool call approval → Approval gates on individual tool calls: auto-allow, prompt, or deny.
Rate Limiting MCP Tool Calls: A Practical Guide →
MCP Security: Why Prompt Guardrails Aren't Enough →

FAQ

Questions about system_shutdown

What does the system_shutdown tool do? +

Shut down the TrueNAS system. This is a DESTRUCTIVE operation — the system will power off and require physical or IPMI intervention to restart. The. It is categorised as a Destructive tool in the Truenas 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 system_shutdown? +

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

What risk level is system_shutdown? +

system_shutdown 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 system_shutdown? +

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

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

system_shutdown is provided by the Truenas MCP server (spranab/truenas-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.

Enforce policy on every Truenas tool call.

Start from Truenas, add the rest of your stack, and see everything your agents can call. Then put policy on all of it.

CHECK YOUR STACK →