ftp_upload · Ftp MCP: Risk & Policy

WHAT IT DOES

What ftp_upload does on Ftp

AI agents use ftp_upload 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_upload needs a policy

ftp_upload creates or modifies files on a remote FTP/SFTP server. While reversible (unlike ftp_delete), it can overwrite existing data and deploy potentially malicious content to production systems, making it a Write-category risk. Severity is high because an AI agent given unconstrained upload access could compromise server integrity, inject malware, or overwrite critical application files.

From the tool's definition Tool name 'ftp_upload' and description 'Standard single-file transport to the remote server' indicate file creation/modification on a remote system.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

ftp_upload Rate-limited

ftp_upload 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_upload": {
      "limits": [
        {
          "counter": "ftp_upload_rate",
          "window": "minute",
          "max": 30,
          "scope": "grant"
        }
      ]
    }
  }
}

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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_upload

What does the ftp_upload tool do? +

Standard single-file transport to the remote server. For bulk transfers, favor ftp_batch_upload. 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_upload? +

Register the Ftp MCP server in PolicyLayer and add a rule for ftp_upload: 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_upload? +

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

Can I rate-limit ftp_upload? +

Yes. Add a rate_limit block to the ftp_upload 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_upload completely? +

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

ftp_upload 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.