login-user

Q: What risk level is login-user?

login-user is a Other tool with low risk. Read-only tools are generally safe to allow by default.

THE RISK

Low Risk

Why login-user needs a policy

Login/authentication does not itself read, write, execute, destroy, or move money — it establishes a session. However, misuse (e.g., credential theft, privilege escalation, or opening a session that enables destructive SCADA operations) gives it a medium severity. Closest category is Other since authentication is a prerequisite action, not a data or execution action in itself.

From the tool's definition Authenticates a user in WinCC Unified using a provided username and password

Documented attack patterns abuse exactly the kind of access login-user gives an agent:

POLICY

How to control login-user

PolicyLayer is an MCP gateway — it sits between your AI agents and WinCC Unified MCP XT, and nothing reaches the server without passing your rules. This is the rule we recommend for login-user:

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "login-user": {
      "limits": [
        {
          "counter": "login-user_rate",
          "window": "minute",
          "max": 60,
          "scope": "grant"
        }
      ]
    }
  }
}

Create a free account and register WinCC Unified MCP XT — nothing to install.
Add this policy — paste it, or build it visually.
Point your MCP client (Claude, Cursor, anything) at your gateway URL.

SET A RULE FOR THIS TOOL →

Free to start. No card required.

EXPLORE

Related tools and policies

More WinCC Unified MCP XT tools

Execute reset-alarms Resets one or more active alarms based on their identifiers. Execute acknowledge-alarms Acknowledges one or more active alarms based on their identifiers. Write write-tag-values Updates tag values based on a provided list of TagValueInput entries. Read browse-objects Retrieves tags, elements, types, alarms, logging tags, and other named objects based on sp Read get-active-alarms Retrieves active alarms from the specified systems. Read get-logged-alarms Retrieves historical (logged) alarms from the storage system. Read get-logged-tag-values Retrieves historical tag values from the database for the specified tags or logging tags. Read get-tag-values Retrieves tag values from WinCC Unified based on the provided names or filter criteria.

All 9 WinCC Unified MCP XT tools →

Other tools on other servers

Android Forensics ADB MCP Server generate_app_analysis_report Ethereum Tools add Math MCP Server complex_analysis_suite Crypto_MCP aes_encrypt

Go deeper

The MCP Attack Database → Documented attack patterns against MCP deployments — and the policies that stop them.
Tool risk categories → How PolicyLayer classifies MCP tools by what they can do.
MCP tool → What an MCP tool is and how clients discover and call it.
Rate Limiting MCP Tool Calls: A Practical Guide →
MCP Security: Why Prompt Guardrails Aren't Enough →

FAQ

Questions about login-user

What does the login-user tool do? +

Authenticates a user in WinCC Unified using a provided username and password. It is categorised as a Other tool in the WinCC Unified MCP XT MCP Server, which means it performs auxiliary operations.

How do I enforce a policy on login-user? +

Register the WinCC Unified MCP XT MCP server in PolicyLayer and add a rule for login-user: 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 WinCC Unified MCP XT. Nothing to install.

What risk level is login-user? +

Can I rate-limit login-user? +

Yes. Add a rate_limit block to the login-user 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 login-user completely? +

Set action: deny in the PolicyLayer policy for login-user. 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 login-user? +

login-user is provided by the WinCC Unified MCP XT MCP server (mrwan84/wincc-unified-mcp-xt). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.

Enforce policy on every WinCC Unified MCP XT tool call.

Start from WinCC Unified MCP XT, add the rest of your stack, and see everything your agents can call. Then put policy on all of it.

CHECK YOUR STACK →