port-forward · Kubernetes MCP Server MCP: Risk & Policy

WHAT IT DOES

What port-forward does on Kubernetes MCP Server

AI agents invoke port-forward to trigger actions in Kubernetes 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 port-forward needs a policy

Port-forwarding is an active operation that spawns a background process and opens a network connection, enabling external access to internal cluster services. It is not a simple read/query, but an execution of an ongoing network operation. Misuse could expose internal services to unintended access, hence medium severity.

From the tool's definition 'Port forward a Kubernetes service to a local port' — actively establishes a network tunnel/process that routes traffic between local and cluster resources

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

port-forward Rate-limited

port-forward 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": {
    "port-forward": {
      "limits": [
        {
          "counter": "port-forward_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 Kubernetes MCP Server, so you can run agents against it safely.

FAQ

Questions about port-forward

What does the port-forward tool do? +

Port forward a Kubernetes service to a local port. It is categorised as a Execute tool in the Kubernetes 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 port-forward? +

Register the Kubernetes MCP Server MCP server in PolicyLayer and add a rule for port-forward: 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 Kubernetes MCP Server. Nothing to install.

What risk level is port-forward? +

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

Can I rate-limit port-forward? +

Yes. Add a rate_limit block to the port-forward 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 port-forward completely? +

Set action: deny in the PolicyLayer policy for port-forward. 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 port-forward? +

port-forward is provided by the Kubernetes MCP Server MCP server (thekaranpargaie/kube-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.