solve_captcha · LMS MCP Server MCP: Risk & Policy

WHAT IT DOES

What solve_captcha does on LMS MCP Server

AI agents invoke solve_captcha to trigger actions in LMS MCP Server. What it does depends on the arguments the agent supplies, and its effects often reach beyond the immediate call — builds kicked off, notifications sent, workflows started.

WHY IT NEEDS A POLICY

Why solve_captcha needs a policy

Solving a CAPTCHA is an execution action that bypasses an authentication security mechanism. It runs OCR processing on an image and returns a solution used to defeat bot-detection. This is not a passive read but an active operation with side effects on the authentication flow. Severity is medium because misuse could enable unauthorized access to the LMS, though it does not directly destroy data or move money.

From the tool's definition 'Solve CAPTCHA challenges using OCR' — actively processes and solves a security challenge using optical character recognition, triggering an external computation/operation

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

solve_captcha Rate-limited

solve_captcha stays usable, but rate-capped — a runaway agent can't fire it dozens of times a minute. Everything else on the server is denied unless you say otherwise.

View as policy code

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "solve_captcha": {
      "limits": [
        {
          "counter": "solve_captcha_rate",
          "window": "minute",
          "max": 10,
          "scope": "grant"
        }
      ]
    }
  }
}

RATE-LIMIT THIS TOOL →

Instant setup, no code required.

PolicyLayer is an MCP gateway: every tool call is checked against your rule before it reaches LMS MCP Server, so you can run agents against it safely.

FAQ

Questions about solve_captcha

What does the solve_captcha tool do? +

Solve CAPTCHA challenges using OCR. It is categorised as a Execute tool in the LMS MCP Server MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.

How do I enforce a policy on solve_captcha? +

Register the LMS MCP Server MCP server in PolicyLayer and add a rule for solve_captcha: 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 LMS MCP Server. Nothing to install.

What risk level is solve_captcha? +

solve_captcha is a Execute tool with high risk. Execute tools should be rate-limited and have argument validation enabled.

Can I rate-limit solve_captcha? +

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

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

solve_captcha is provided by the LMS MCP Server MCP server (qaziabsaar/lms_mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.