updatePassword · MCP-YNU FastMCP Server MCP: Risk & Policy

WHAT IT DOES

What updatePassword does on MCP-YNU FastMCP Server

AI agents use updatePassword to create or update resources in MCP-YNU FastMCP Server — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your MCP-YNU FastMCP Server environment.

WHY IT NEEDS A POLICY

Why updatePassword needs a policy

This tool modifies user account passwords, which is a reversible write operation (passwords can be changed again). However, it carries high severity because unauthorized password changes could grant an AI agent control over user accounts and email access, potentially compromising account security and enabling further attacks.

From the tool's definition Tool description states '修改 coremail 用户 user_at_domain 的密码为 password' (Modify coremail user's password). The terms '修改' (modify/change) and '密码' (password) indicate a write operation that modifies user account credentials.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

updatePassword Rate-limited

updatePassword 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": {
    "updatePassword": {
      "limits": [
        {
          "counter": "updatepassword_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 MCP-YNU FastMCP Server, so you can run agents against it safely.

FAQ

Questions about updatePassword

What does the updatePassword tool do? +

修改 coremail 用户 user_at_domain 的密码为 password. It is categorised as a Write tool in the MCP-YNU FastMCP Server MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on updatePassword? +

Register the MCP-YNU FastMCP Server MCP server in PolicyLayer and add a rule for updatePassword: 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 MCP-YNU FastMCP Server. Nothing to install.

What risk level is updatePassword? +

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

Can I rate-limit updatePassword? +

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

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

updatePassword is provided by the MCP-YNU FastMCP Server MCP server (ynu/mcp-ynu). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.