Medium Risk

smb_share_create

Create a new SMB share

How to control smb_share_create ↓

What smb_share_create does on Truenas

AI agents use smb_share_create 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 smb_share_create needs a policy

Creating SMB shares modifies the system configuration by adding new network-accessible resources. While not destructive (shares can be deleted), this is a Write action that creates persistent configuration changes with security implications—misconfigured shares could expose sensitive data or expand attack surface.

From the tool's definition Tool name 'smb_share_create' and description 'Create a new SMB share' indicate irreversible creation of a network resource. This creates persistent SMB (Samba/CIFS) shares that expose filesystem paths to network clients.

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

How to control smb_share_create

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 smb_share_create:

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

smb_share_create 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 →

Free to start. No card required.

Related tools and policies

Go deeper

Questions about smb_share_create

What does the smb_share_create tool do? +

Create a new SMB share. 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 smb_share_create? +

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

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

Can I rate-limit smb_share_create? +

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

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

smb_share_create 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.

Free to start. No card required.

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