Medium Risk

privilege_update

Update an existing privilege/role by its ID. Use privilege_list to find the ID. All fields are optional.

How to control privilege_update ↓

What privilege_update does on Truenas

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

Medium Risk

Why privilege_update needs a policy

This tool modifies (but does not irreversibly delete) privilege/role definitions in a TrueNAS system. Updating privileges affects access control policies and can grant or restrict permissions for users and roles. While reversible (Write category), the severity is high because misconfiguration of privilege/roles could grant unintended elevated access or lock out legitimate users.

From the tool's definition Tool name 'privilege_update' combined with description stating it 'Update[s] an existing privilege/role by its ID.' The action modifies system access controls and permissions which are critical security configurations.

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

How to control privilege_update

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 privilege_update:

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

privilege_update 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 Truenas — 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 →

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Related tools and policies

Go deeper

Questions about privilege_update

What does the privilege_update tool do? +

Update an existing privilege/role by its ID. Use privilege_list to find the ID. All fields are optional. It is categorised as a Write tool in the Truenas MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on privilege_update? +

Register the Truenas MCP server in PolicyLayer and add a rule for privilege_update: 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 privilege_update? +

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

Can I rate-limit privilege_update? +

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

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

privilege_update 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.

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279 Truenas tools catalogued and risk-classified — across an index of 43,000+ MCP servers.

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