hijack_send · Mcp Bbs MCP: Risk & Policy

WHAT IT DOES

What hijack_send does on Mcp Bbs

AI agents invoke hijack_send to trigger actions in Mcp Bbs. 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 hijack_send needs a policy

This tool sends input to a remotely controlled bot session, triggering external operations on a legacy BBS system. The 'hijacked bot' framing implies taking over an active session and injecting commands, which constitutes executing operations on an external system.

From the tool's definition 'Send input to a hijacked bot' — actively sends input/commands to an assumed/hijacked bot session on an external BBS system

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

hijack_send Rate-limited

hijack_send 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": {
    "hijack_send": {
      "limits": [
        {
          "counter": "hijack_send_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 Mcp Bbs, so you can run agents against it safely.

FAQ

Questions about hijack_send

What does the hijack_send tool do? +

Send input to a hijacked bot, optionally guarded by prompt/regex. It is categorised as a Execute tool in the Mcp Bbs MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.

How do I enforce a policy on hijack_send? +

Register the Mcp Bbs MCP server in PolicyLayer and add a rule for hijack_send: 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 Mcp Bbs. Nothing to install.

What risk level is hijack_send? +

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

Can I rate-limit hijack_send? +

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

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

hijack_send is provided by the Mcp Bbs MCP server (livingstaccato/mcp-bbs). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.