enable_pyfilter · Firegex MCP: Risk & Policy

WHAT IT DOES

What enable_pyfilter does on Firegex

AI agents use enable_pyfilter to create or update resources in Firegex — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your Firegex environment.

WHY IT NEEDS A POLICY

Why enable_pyfilter needs a policy

Enabling a pyfilter modifies the state of the firewall/proxy system by activating a filter rule. This is a reversible state change (it can be disabled again), placing it in the Write category. The blast radius is medium because enabling an incorrect or malicious filter could affect traffic filtering behavior in the CTF firewall proxy, potentially allowing or blocking unintended traffic.

From the tool's definition "Enable a single pyfilter by name" — activates/enables an existing filter configuration

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

enable_pyfilter Rate-limited

enable_pyfilter stays usable, but capped — an agent stuck in a loop can't make hundreds of changes a minute. Everything else on the server is denied unless you say otherwise.

View as policy code

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "enable_pyfilter": {
      "limits": [
        {
          "counter": "enable_pyfilter_rate",
          "window": "minute",
          "max": 30,
          "scope": "grant"
        }
      ]
    }
  }
}

LIMIT THIS TOOL →

Instant setup, no code required.

PolicyLayer is an MCP gateway: every tool call is checked against your rule before it reaches Firegex, so you can run agents against it safely.

FAQ

Questions about enable_pyfilter

What does the enable_pyfilter tool do? +

Enable a single pyfilter by name. It is categorised as a Write tool in the Firegex MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on enable_pyfilter? +

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

What risk level is enable_pyfilter? +

enable_pyfilter is a Write tool with medium risk. Write tools should be rate-limited to prevent accidental bulk modifications.

Can I rate-limit enable_pyfilter? +

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

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

enable_pyfilter is provided by the Firegex MCP server (umbra2728/firegex-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.