attach_user_policy · Amazon MQ MCP Server MCP: Risk & Policy

WHAT IT DOES

What attach_user_policy does on Amazon MQ MCP Server

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

WHY IT NEEDS A POLICY

Why attach_user_policy needs a policy

Attaching a user policy modifies access controls and permissions, granting new capabilities to IAM users. This is a Write operation because it creates/modifies data structures reversibly. Severity is high because misconfigured policies could grant overly broad permissions, creating security risks.

From the tool's definition Tool name 'attach_user_policy' indicates attaching a policy to a user, which modifies IAM permissions. No description provided, but the sibling tool 'add_inline_policy' (on the same server) confirms policy attachment operations are supported.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

attach_user_policy Rate-limited

attach_user_policy 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": {
    "attach_user_policy": {
      "limits": [
        {
          "counter": "attach_user_policy_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 Amazon MQ MCP Server, so you can run agents against it safely.

FAQ

Questions about attach_user_policy

What does the attach_user_policy tool do? +

attach_user_policy. It is categorised as a Write tool in the Amazon MQ MCP 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 attach_user_policy? +

Register the Amazon MQ MCP Server MCP server in PolicyLayer and add a rule for attach_user_policy: 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 Amazon MQ MCP Server. Nothing to install.

What risk level is attach_user_policy? +

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

Can I rate-limit attach_user_policy? +

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

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

attach_user_policy is provided by the Amazon MQ MCP Server MCP server (awslabs.amazon-mq-mcp-server). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.