High Risk →

exec

Executes arbitrary commands inside a running Docker container and returns structured output. WARNING: may execute untrusted code.

How to control exec ↓

What exec does on Http

AI agents invoke exec to trigger actions in Http. 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.

High Risk

Why exec needs a policy

This tool executes arbitrary commands with no restrictions mentioned, making it an Execute category risk. The critical severity reflects the extremely high blast radius: an AI agent given this tool could execute any command (including destructive ones like rm -rf, data exfiltration, lateral movement, malware deployment) inside a container.

From the tool's definition Tool description explicitly states 'Executes arbitrary commands inside a running Docker container' and includes warning 'WARNING: may execute untrusted code.'

Documented attack patterns abuse exactly the kind of access exec gives an agent:

How to control exec

PolicyLayer is an MCP gateway — it sits between your AI agents and Http, and nothing reaches the server without passing your rules. This is the rule we recommend for exec:

policy.json
{
  "version": "1",
  "default": "deny",
  "tools": {
    "exec": {
      "limits": [
        {
          "counter": "exec_rate",
          "window": "minute",
          "max": 10,
          "scope": "grant"
        }
      ]
    }
  }
}

exec 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.

  1. Create a free account and register Http — nothing to install.
  2. Add this policy — paste it, or build it visually.
  3. Point your MCP client (Claude, Cursor, anything) at your gateway URL.
RATE-LIMIT THIS TOOL →

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Related tools and policies

Go deeper

Questions about exec

What does the exec tool do? +

Executes arbitrary commands inside a running Docker container and returns structured output. WARNING: may execute untrusted code. It is categorised as a Execute tool in the Http MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.

How do I enforce a policy on exec? +

Register the Http MCP server in PolicyLayer and add a rule for exec: 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 Http. Nothing to install.

What risk level is exec? +

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

Can I rate-limit exec? +

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

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

exec is provided by the Http MCP server (@paretools/http). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.

Enforce policy on every Http tool call.

Start from Http, add the rest of your stack, and see everything your agents can call. Then put policy on all of it.

Free to start. No card required.

202 Http tools catalogued and risk-classified — across an index of 43,000+ MCP servers.

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