proxy_remove_host_upstream

THE RISK

Critical Risk

Why proxy_remove_host_upstream needs a policy

This tool irreversibly removes a configuration entry (per-host upstream proxy override). Deletion of proxy routing rules cannot be undone automatically and could disrupt traffic routing for affected hosts.

From the tool's definition Remove a per-host upstream proxy override

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

POLICY

How to control proxy_remove_host_upstream

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

policy.json

{
  "version": "1",
  "default": "deny",
  "hide": [
    "proxy_remove_host_upstream"
  ]
}

proxy_remove_host_upstream disappears from the agent's tool list entirely, and any attempt to call it is denied. The rest of the server keeps working.

Create a free account and register Proxy — nothing to install.
Add this policy — paste it, or build it visually.
Point your MCP client (Claude, Cursor, anything) at your gateway URL.

RESTRICT THIS TOOL →

Free to start. No card required.

EXPLORE

Related tools and policies

More Proxy tools

Destructive interceptor_docker_detach Remove proxy configuration from a Docker container and clean up injected files. Destructive proxy_clear_traffic Clear all captured traffic from the buffer. Destructive proxy_delete_session Delete a recorded session from disk. Destructive proxy_remove_rule Delete an interception rule. Destructive proxy_session_stop Stop persistent on-disk capture and finalize the active session. Destructive interceptor_deactivate_all Kill ALL active interceptors across all types. Emergency cleanup — stops all browser insta Destructive interceptor_kill Kill a spawned process by target ID. Also retrieves final stdout/stderr output. Destructive proxy_mobile_teardown Reverse proxy_mobile_setup: deactivate the Android target if any, stop the transparent + e

All 89 Proxy tools →

Destructive tools on other servers

Android Forensics ADB MCP Server create_full_backup 0xarchive web3_revoke_key Frida Game Hacking MCP clear_scan cPanel MCP Server clear_spam_box

Go deeper

Critical-risk tools in Proxy → Every critical-risk tool this server exposes, in one view.
All critical-risk MCP tools → Every critical-risk tool across the catalogue, and the policy pattern that contains them.
The MCP Attack Database → Documented attack patterns against MCP deployments — and the policies that stop them.
Blast radius → How much damage one compromised or confused agent can do — and how to bound it.
Tool call approval → Approval gates on individual tool calls: auto-allow, prompt, or deny.
Rate Limiting MCP Tool Calls: A Practical Guide →
MCP Security: Why Prompt Guardrails Aren't Enough →

FAQ

Questions about proxy_remove_host_upstream

What does the proxy_remove_host_upstream tool do? +

Remove a per-host upstream proxy override. It is categorised as a Destructive tool in the Proxy MCP Server, which means it can permanently delete or destroy data. Block by default and require explicit approval.

How do I enforce a policy on proxy_remove_host_upstream? +

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

What risk level is proxy_remove_host_upstream? +

proxy_remove_host_upstream is a Destructive tool with critical risk. Critical-risk tools should be blocked by default and only enabled with explicit human approval.

Can I rate-limit proxy_remove_host_upstream? +

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

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

proxy_remove_host_upstream is provided by the Proxy MCP server (yfe404/proxy-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.

Enforce policy on every Proxy tool call.

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

CHECK YOUR STACK →