hijack_heartbeat · Mcp Bbs MCP: Risk & Policy

WHAT IT DOES

What hijack_heartbeat does on Mcp Bbs

AI agents invoke hijack_heartbeat 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_heartbeat needs a policy

The tool extends a 'hijack lease', which in the context of a BBS telnet client likely means maintaining or prolonging control over a BBS session that was taken over (hijacked). This is an active operation that triggers an external state change (keeping a session alive/controlled), placing it in Execute.

From the tool's definition 'Extend a hijack lease' — the term 'hijack' implies taking control of an external session or connection, and extending a lease is an active operation that prolongs that control state

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

hijack_heartbeat Rate-limited

hijack_heartbeat 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_heartbeat": {
      "limits": [
        {
          "counter": "hijack_heartbeat_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_heartbeat

What does the hijack_heartbeat tool do? +

Extend a hijack lease. 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_heartbeat? +

Register the Mcp Bbs MCP server in PolicyLayer and add a rule for hijack_heartbeat: 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_heartbeat? +

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

Can I rate-limit hijack_heartbeat? +

Yes. Add a rate_limit block to the hijack_heartbeat 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_heartbeat completely? +

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

hijack_heartbeat 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.