ftp_chmod · Ftp MCP: Risk & Policy

WHAT IT DOES

What ftp_chmod does on Ftp

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

WHY IT NEEDS A POLICY

Why ftp_chmod needs a policy

ftp_chmod modifies file permission metadata on a remote server. This is a Write operation (reversible attribute change), not Destructive. However, the blast radius is high because misconfigured permissions can expose sensitive files publicly, lock out legitimate users, or create privilege escalation vectors on the remote system.

From the tool's definition Change remote file permissions

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

ftp_chmod Rate-limited

ftp_chmod 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.

View as policy code

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "ftp_chmod": {
      "limits": [
        {
          "counter": "ftp_chmod_rate",
          "window": "minute",
          "max": 30,
          "scope": "grant"
        }
      ]
    }
  }
}

LIMIT THIS TOOL →

Instant setup, no code required.

PolicyLayer is an MCP gateway: every tool call is checked against your rule before it reaches Ftp, so you can run agents against it safely.

FAQ

Questions about ftp_chmod

What does the ftp_chmod tool do? +

Change remote file permissions. CRITICAL: Only supported on SFTP connections. It is categorised as a Write tool in the Ftp MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on ftp_chmod? +

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

What risk level is ftp_chmod? +

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

Can I rate-limit ftp_chmod? +

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

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

ftp_chmod is provided by the Ftp MCP server (kynlos/ftp-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.

// THE FULL RECORD

ftp_chmod is one line of Ftp's registry record.

The record carries the whole server: verified identity, auth posture, risk grade, every tool classified, recommended policy — re-checked continuously.

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