rubeus_hash · Rubeus MCP Server MCP: Risk & Policy

WHAT IT DOES

What rubeus_hash does on Rubeus MCP Server

AI agents invoke rubeus_hash 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_hash needs a policy

This tool executes a cryptographic operation (hash computation) on plaintext passwords, producing credential material (NTLM hashes, AES keys) that can be directly used for Kerberos ticket requests and pass-the-hash/pass-the-key attacks.

From the tool's definition Calculate Kerberos password hashes from plaintext... Computes the various Kerberos encryption keys from a password: RC4_HMAC (NTLM), AES128_CTS_HMAC_SHA1, AES256_CTS_HMAC_SHA1, DES_CBC_MD5

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

rubeus_hash Rate-limited

rubeus_hash 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_hash": {
      "limits": [
        {
          "counter": "rubeus_hash_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_hash

What does the rubeus_hash tool do? +

Calculate Kerberos password hashes from plaintext. Computes the various Kerberos encryption keys from a password: - RC4_HMAC (NTLM) - AES128_CTS_HMAC_SHA1 - AES256_CTS_HMAC_SHA1 - DES_CBC_MD5 These hashes can be used for ticket requests and other operations. 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_hash? +

Register the Rubeus MCP Server MCP server in PolicyLayer and add a rule for rubeus_hash: 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_hash? +

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

Can I rate-limit rubeus_hash? +

Yes. Add a rate_limit block to the rubeus_hash 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_hash completely? +

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

rubeus_hash 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.