Securely Execute Commands on Windows and Remote Systems

Windows CLI MCP Server

MCP server for secure command-line interactions on Windows systems, enabling controlled access to PowerShell, CMD, Git Bash shells, and remote systems via SSH. It allows MCP clients (like Claude Desktop) to perform operations on your system, similar to Open Interpreter.

• Features
• Usage with Claude Desktop
• Configuration
  • Configuration Locations
  • Default Configuration
  • Configuration Settings
    • Security Settings
    • Shell Configuration
    • SSH Configuration
• API
  • Tools
  • Resources
• Security Considerations
• License

Features

• Multi-Shell Support: Execute commands in PowerShell, Command Prompt (CMD), and Git Bash
• SSH Support: Execute commands on remote systems via SSH
• Resource Exposure: View SSH connections, current directory, and configuration as MCP resources
• Security Controls:
  • Command and SSH command blocking (full paths, case variations)
  • Working directory validation
  • Maximum command length limits
  • Command logging and history tracking
  • Smart argument validation
• Configurable:
  • Custom security rules
  • Shell-specific settings
  • SSH connection profiles
  • Path restrictions
  • Blocked command lists

See the API section for more details on the tools and resources the server provides to MCP clients.

Note: The server will only allow operations within configured directories, with allowed commands, and on configured SSH connections.

Usage with Claude Desktop

Add this to your claude_desktop_config.json:

{
  "mcpServers": {
    "windows-cli": {
      "command": "npx",
      "args": ["-y", "@simonb97/server-win-cli"]
    }
  }
}

For use with a specific config file, add the --config flag:

{
  "mcpServers": {
    "windows-cli": {
      "command": "npx",
      "args": [
        "-y",
        "@simonb97/server-win-cli",
        "--config",
        "path/to/your/config.json"
      ]
    }
  }
}

After configuring, you can:

• Execute commands directly using the available tools
• View configured SSH connections and server configuration in the Resources section
• Manage SSH connections through the provided tools

Configuration

The server uses a JSON configuration file to customize its behavior. You can specify settings for security controls, shell configurations, and SSH connections.

1. To create a default config file, either:

a) copy config.json.example to config.json, or

b) run:

npx @simonb97/server-win-cli --init-config ./config.json

2. Then set the --config flag to point to your config file as described in the Usage with Claude Desktop section.

Configuration Locations

The server looks for configuration in the following locations (in order):

1. Path specified by --config flag
2. ./config.json in current directory
3. ~/.win-cli-mcp/config.json in user's home directory

If no configuration file is found, the server will use a default (restricted) configuration:

Default Configuration

Note: The default configuration is designed to be restrictive and secure. Find more details on each setting in the Configuration Settings section.

{
  "security": {
    "maxCommandLength": 2000,
    "blockedCommands": [
      "rm",
      "del",
      "rmdir",
      "format",
      "shutdown",
      "restart",
      "reg",
      "regedit",
      "net",
      "netsh",
      "takeown",
      "icacls"
    ],
    "blockedArguments": [
      "--exec",
      "-e",
      "/c",
      "-enc",
      "-encodedcommand",
      "-command",
      "--interactive",
      "-i",
      "--login",
      "--system"
    ],
    "allowedPaths": ["User's home directory", "Current working directory"],
    "restrictWorkingDirectory": true,
    "logCommands": true,
    "maxHistorySize": 1000,
    "commandTimeout": 30,
    "enableInjectionProtection": true
  },
  "shells": {
    "powershell": {
      "enabled": true,
      "command": "powershell.exe",
      "args": ["-NoProfile", "-NonInteractive", "-Command"],
      "blockedOperators": ["&", "|", ";", "`"]
    },
    "cmd": {
      "enabled": true,
      "command": "cmd.exe",
      "args": ["/c"],
      "blockedOperators": ["&", "|", ";", "`"]
    },
    "gitbash": {
      "enabled": true,
      "command": "C:\\Program Files\\Git\\bin\\bash.exe",
      "args": ["-c"],
      "blockedOperators": ["&", "|", ";", "`"]
    }
  },
  "ssh": {
    "enabled": false,
    "defaultTimeout": 30,
    "maxConcurrentSessions": 5,
    "keepaliveInterval": 10000,
    "keepaliveCountMax": 3,
    "readyTimeout": 20000,
    "connections": {}
  }
}

Configuration Settings

The configuration file is divided into three main sections: security, shells, and ssh.

Security Settings

{
  "security": {
    // Maximum allowed length for any command
    "maxCommandLength": 1000,

    // Commands to block - blocks both direct use and full paths
    // Example: "rm" blocks both "rm" and "C:\\Windows\\System32\\rm.exe"
    // Case-insensitive: "del" blocks "DEL.EXE", "del.cmd", etc.
    "blockedCommands": [
      "rm", // Delete files
      "del", // Delete files
      "rmdir", // Delete directories
      "format", // Format disks
      "shutdown", // Shutdown system
      "restart", // Restart system
      "reg", // Registry editor
      "regedit", // Registry editor
      "net", // Network commands
      "netsh", // Network commands
      "takeown", // Take ownership of files
      "icacls" // Change file permissions
    ],

    // Arguments that will be blocked when used with any command
    // Note: Checks each argument independently - "cd warm_dir" won't be blocked just because "rm" is in blockedCommands
    "blockedArguments": [
      "--exec", // Execution flags
      "-e", // Short execution flags
      "/c", // Command execution in some shells
      "-enc", // PowerShell encoded commands
      "-encodedcommand", // PowerShell encoded commands
      "-command", // Direct PowerShell command execution
      "--interactive", // Interactive mode which might bypass restrictions
      "-i", // Short form of interactive
      "--login", // Login shells might have different permissions
      "--system" // System level operations
    ],

    // List of directories where commands can be executed
    "allowedPaths": ["C:\\Users\\YourUsername", "C:\\Projects"],

    // If true, commands can only run in allowedPaths
    "restrictWorkingDirectory": true,

    // If true, saves command history
    "logCommands": true,

    // Maximum number of commands to keep in history
    "maxHistorySize": 1000,

    // Timeout for command execution in seconds (default: 30)
    "commandTimeout": 30,

    // Enable or disable protection against command injection (covers ;, &, |, \`)
    "enableInjectionProtection": true
  }
}

Shell Configuration

{
  "shells": {
    "powershell": {
      // Enable/disable this shell
      "enabled": true,
      // Path to shell executable
      "command": "powershell.exe",
      // Default arguments for the shell
      "args": ["-NoProfile", "-NonInteractive", "-Command"],
      // Optional: Specify which command operators to block
      "blockedOperators": ["&", "|", ";", "`"]  // Block all command chaining
    },
    "cmd": {
      "enabled": true,
      "command": "cmd.exe",
      "args": ["/c"],
      "blockedOperators": ["&", "|", ";", "`"]  // Block all command chaining
    },
    "gitbash": {
      "enabled": true,
      "command": "C:\\Program Files\\Git\\bin\\bash.exe",
      "args": ["-c"],
      "blockedOperators": ["&", "|", ";", "`"]  // Block all command chaining
    }
  }
}

SSH Configuration

{
  "ssh": {
    // Enable/disable SSH functionality
    "enabled": false,

    // Default timeout for SSH commands in seconds
    "defaultTimeout": 30,

    // Maximum number of concurrent SSH sessions
    "maxConcurrentSessions": 5,

    // Interval for sending keepalive packets (in milliseconds)
    "keepaliveInterval": 10000,

    // Maximum number of failed keepalive attempts before disconnecting
    "keepaliveCountMax": 3,

    // Timeout for establishing SSH connections (in milliseconds)
    "readyTimeout": 20000,

    // SSH connection profiles
    "connections": {
      // NOTE: these examples are not set in the default config!
      // Example: Local Raspberry Pi
      "raspberry-pi": {
        "host": "raspberrypi.local", // Hostname or IP address
        "port": 22, // SSH port
        "username": "pi", // SSH username
        "password": "raspberry", // Password authentication (if not using key)
        "keepaliveInterval": 10000, // Override global keepaliveInterval
        "keepaliveCountMax": 3, // Override global keepaliveCountMax
        "readyTimeout": 20000 // Override global readyTimeout
      },
      // Example: Remote server with key authentication
      "dev-server": {
        "host": "dev.example.com",
        "port": 22,
        "username": "admin",
        "privateKeyPath": "C:\\Users\\YourUsername\\.ssh\\id_rsa", // Path to private key
        "keepaliveInterval": 10000,
        "keepaliveCountMax": 3,
        "readyTimeout": 20000
      }
    }
  }
}

API

Tools

• execute_command

  • Execute a command in the specified shell
  • Inputs:
    • shell (string): Shell to use ("powershell", "cmd", or "gitbash")
    • command (string): Command to execute
    • workingDir (optional string): Working directory
  • Returns command output as text, or error message if execution fails

• get_command_history

  • Get the history of executed commands
  • Input: limit (optional number)
  • Returns timestamped command history with outputs

• ssh_execute

  • Execute a command on a remote system via SSH
  • Inputs:
    • connectionId (string): ID of the SSH connection to use
    • command (string): Command to execute
  • Returns command output as text, or error message if execution fails

• ssh_disconnect

  • Disconnect from an SSH server
  • Input:
    • connectionId (string): ID of the SSH connection to disconnect
  • Returns confirmation message

• create_ssh_connection

  • Create a new SSH connection
  • Inputs:
    • connectionId (string): ID for the new SSH connection
    • connectionConfig (object): Connection configuration details including host, port, username, and either password or privateKeyPath
  • Returns confirmation message

• read_ssh_connections

  • Read all configured SSH connections
  • Returns a list of all SSH connections from the configuration

• update_ssh_connection

  • Update an existing SSH connection
  • Inputs:
    • connectionId (string): ID of the SSH connection to update
    • connectionConfig (object): New connection configuration details
  • Returns confirmation message

• delete_ssh_connection

  • Delete an SSH connection
  • Input:
    • connectionId (string): ID of the SSH connection to delete
  • Returns confirmation message

• get_current_directory

  • Get the current working directory of the server
  • Returns the current working directory path

Resources

• SSH Connections

  • URI format: ssh://{connectionId}
  • Contains connection details with sensitive information masked
  • One resource for each configured SSH connection
  • Example: ssh://raspberry-pi shows configuration for the "raspberry-pi" connection

• SSH Configuration

  • URI: ssh://config
  • Contains overall SSH configuration and all connections (with passwords masked)
  • Shows settings like defaultTimeout, maxConcurrentSessions, and the list of connections

• Current Directory

  • URI: cli://currentdir
  • Contains the current working directory of the CLI server
  • Shows the path where commands will execute by default

• CLI Configuration

  • URI: cli://config
  • Contains the CLI server configuration (excluding sensitive data)
  • Shows security settings, shell configurations, and SSH settings

Security Considerations

Built-in Security Features (Always Active)

The following security features are hard-coded into the server and cannot be disabled:

• Case-insensitive command blocking: All command blocking is case-insensitive (e.g., "DEL.EXE", "del.cmd", etc. are all blocked if "del" is in blockedCommands)
• Smart path parsing: The server parses full command paths to prevent bypass attempts (blocking "C:\Windows\System32\rm.exe" if "rm" is blocked)
• Command parsing intelligence: False positives are avoided (e.g., "warm_dir" is not blocked just because "rm" is in blockedCommands)
• Input validation: All user inputs are validated before execution
• Shell process management: Processes are properly terminated after execution or timeout
• Sensitive data masking: Passwords are automatically masked in resources (replaced with ********)

Configurable Security Features (Active by Default)

These security features are configurable through the config.json file:

• Command blocking: Commands specified in blockedCommands array are blocked (default includes dangerous commands like rm, del, format)
• Argument blocking: Arguments specified in blockedArguments array are blocked (default includes potentially dangerous flags)
• Command injection protection: Prevents command chaining (enabled by default through enableInjectionProtection: true)
• Working directory restriction: Limits command execution to specified directories (enabled by default through restrictWorkingDirectory: true)
• Command length limit: Restricts maximum command length (default: 2000 characters)
• Command timeout: Terminates commands that run too long (default: 30 seconds)
• Command logging: Records command history (enabled by default through logCommands: true)

Important Security Warnings

These are not features but important security considerations to be aware of:

• Environment access: Commands may have access to environment variables, which could contain sensitive information
• File system access: Commands can read/write files within allowed paths - carefully configure allowedPaths to prevent access to sensitive data