| name | hardening-local |
| description | Harden locally deployed MCP servers against network exposure and host compromise. Use when building, deploying, or reviewing MCP servers that run on a user's local machine. |
| category | secure_development |
| subcategory | mcp-server |
Hardening Local MCP Servers
Security Requirements
MCP servers running locally on a user's machine require specific hardening to prevent network exposure and protect the host.
Network Binding
Bind to the loopback interface only:
# CORRECT - bind to loopback only
host: 127.0.0.1
port: 8080
# WRONG - exposed to the entire network
host: 0.0.0.0
port: 8080
Binding to 0.0.0.0 exposes the MCP server to the local network and potentially the internet, allowing unauthorized access.
Process Isolation
| Control | Details |
|---|
| Dedicated user | Run as a dedicated low-privilege OS user, not the user's main account |
| No root | Never run as root |
| Minimal permissions | Grant only the filesystem and network permissions needed |
| Filesystem isolation | Use containers or chroot to limit host filesystem access |
Host Protection
| Control | Details |
|---|
| Containers | Run in a container (Podman, Docker) to isolate from the host |
| chroot | Use chroot jail to limit filesystem visibility |
| Read-only access | Mount host directories as read-only unless the server requires write access |
| No home directory access | Do not grant access to the user's entire home directory |
Implementation Checklist
