rubeus_asrep2kirbi · Rubeus MCP Server MCP: Risk & Policy

WHAT IT DOES

What rubeus_asrep2kirbi does on Rubeus MCP Server

AI agents invoke rubeus_asrep2kirbi to trigger actions in Rubeus 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 rubeus_asrep2kirbi needs a policy

This tool is part of a Kerberos abuse toolkit (Rubeus) and converts raw AS-REP responses into usable kirbi ticket format, enabling further Kerberos-based attacks (e.g., pass-the-ticket). While the conversion itself is a transformation operation, it produces an actionable credential artifact and runs within an offensive security context.

From the tool's definition Convert an AS-REP response to kirbi ticket format... converts it to a usable kirbi ticket using the provided key

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

rubeus_asrep2kirbi Rate-limited

rubeus_asrep2kirbi 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": {
    "rubeus_asrep2kirbi": {
      "limits": [
        {
          "counter": "rubeus_asrep2kirbi_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 Rubeus MCP Server, so you can run agents against it safely.

FAQ

Questions about rubeus_asrep2kirbi

What does the rubeus_asrep2kirbi tool do? +

Convert an AS-REP response to kirbi ticket format. Takes a raw AS-REP response and converts it to a usable kirbi ticket using the provided key. It is categorised as a Execute tool in the Rubeus 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 rubeus_asrep2kirbi? +

Register the Rubeus MCP Server MCP server in PolicyLayer and add a rule for rubeus_asrep2kirbi: 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 Rubeus MCP Server. Nothing to install.

What risk level is rubeus_asrep2kirbi? +

rubeus_asrep2kirbi is a Execute tool with high risk. Execute tools should be rate-limited and have argument validation enabled.

Can I rate-limit rubeus_asrep2kirbi? +

Yes. Add a rate_limit block to the rubeus_asrep2kirbi 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 rubeus_asrep2kirbi completely? +

Set action: deny in the PolicyLayer policy for rubeus_asrep2kirbi. 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 rubeus_asrep2kirbi? +

rubeus_asrep2kirbi is provided by the Rubeus MCP Server MCP server (schwarztim/sec-rubeus-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.