OS Tool Security for MCP Servers

Security Requirement

When MCP servers execute tools in the operating system, they run with the permissions of the MCP server process. The following security controls are required:

1. Least Privilege: Give the MCP server the lowest permissions necessary to perform its mission.
2. Privilege Dropping: Drop specific privileges before executing specific commands.
3. Sandboxing: Use sandboxing mechanisms to prevent executed commands from causing damage.

Command Execution Hygiene

Never pass unsanitized input to a shell. Use safe, parameterized APIs:

import subprocess

# CORRECT - parameterized, no shell
subprocess.run(['echo', user_input], shell=False)