put_user_policy

A write tool on the AWS MCP server.

SERVERAWS SOURCE@awslabs/mcp

Medium RISK CLASS

Category Write

Parameters 00 required

Recommended Rate-limitedsee the rule below

Registry record Grade F, identity verified Pull the record →

This record as markdown: /tools/aws/put-user-policy.md

WHAT IT DOES

What put_user_policy does on AWS

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

RISK

Why put_user_policy is rated Medium

This tool creates or updates an inline policy for an AWS user, which is a reversible Write operation that changes IAM permissions. It does not delete (Destructive), execute arbitrary code (Execute), or move money (Financial). The severity is high because misconfigured or malicious policies can grant unintended access to sensitive AWS resources, but the operation itself is not irreversible.

From the tool's definition Tool name 'put_user_policy' combined with AWS context and sibling tools like 'attach_user_policy' and 'attach_group_policy'. The 'put_*' pattern in AWS APIs typically creates or updates resources.

Attacks that exploit this kind of access

RECOMMENDED RULE

The rule that runs put_user_policy safely

PolicyLayer is an MCP gateway: it sits between your AI agents and AWS, and checks every tool call against a rule you set before the call runs. Nothing changes on the server itself. For put_user_policy, this is the rule to start with:

put_user_policy Rate-limited

put_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": {
    "put_user_policy": {
      "limits": [
        {
          "counter": "put_user_policy_rate",
          "window": "minute",
          "max": 30,
          "scope": "grant"
        }
      ]
    }
  }
}

LIMIT THIS TOOL → Instant setup, no code required.

The button opens the PolicyLayer dashboard: create your workspace, connect AWS, apply this rule, and every put_user_policy call is checked against it from then on.

FAQ

Questions about put_user_policy

What does the put_user_policy tool do? +

put_user_policy is a write tool on the AWS MCP server. It is categorised as a Write tool in the AWS MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on put_user_policy? +

Register the AWS MCP server in PolicyLayer and add a rule for put_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 AWS. Nothing to install.

What risk level is put_user_policy? +

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

Can I rate-limit put_user_policy? +

Yes. Add a rate_limit block to the put_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 put_user_policy completely? +

Set action: deny in the PolicyLayer policy for put_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 put_user_policy? +

put_user_policy is provided by the AWS MCP server (@awslabs/mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.

KEEP EXPLORING

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