Vulnerable MCP Server: Outdated Packages (Supply Chain)

This is an intentionally vulnerable MCP server that provides basic, read-only filesystem/system inspection tools.

The primary purpose of this lab is to demonstrate supply chain risk from outdated, deprecated, and vulnerable dependency versions.

Do not use this outside a controlled lab environment.

What it provides

The server exposes these MCP tools:

• get_folder_size: Calculate the total size of a folder (bytes + MB)
  • Expects: { "path": "<absolute-folder-path>" }
• list_directory: List files/directories in a path
  • Expects: { "path": "<absolute-directory-path>" }
• get_system_info: Return OS/CPU/memory/hostname/home/tmp details
  • No arguments
• check_path_exists: Check whether a path exists
  • Expects: { "path": "<absolute-path>" }
• get_file_stats: Return file/directory stats (size/timestamps/permissions)
  • Expects: { "path": "<absolute-path>" }

How it is vulnerable

This package intentionally pins older, deprecated, and/or vulnerable dependency versions in package.json so that:

• npm audit produces findings
• dependency scanners can demonstrate detection/reporting
• you can discuss how “works fine” != “safe to run”

Examples of intentionally-problematic dependencies include:

• request (deprecated/unmaintained)
• lodash pinned to an older version
• other old ecosystem packages that frequently appear in audits

This is a supply chain demonstration: in real systems, known-vulnerable packages can be exploited directly, or used as stepping stones (prototype pollution, SSRF, ReDoS, etc.), depending on where/how they are used.

Requirements

• Node.js (the package declares >=14, but using a modern Node LTS is recommended)
• npm

Install dependencies in this folder:

npm install

Run with Claude (using claude_config.json)

This folder includes claude_config.json, which is a ready-to-merge snippet for Claude's MCP server config.

1. Install dependencies:

npm install

2. Edit claude_config.json and replace the placeholder:

• /full/path/to/vulnerable-mcp-server-outdated-pacakges/index.js

Use an absolute path.

3. Open Claude and edit its MCP configuration (Claude Desktop typically exposes this under Settings -> Developer -> Edit config).

4. Merge the mcpServers entry into your config. If you already have mcpServers, add just the server entry:

{
  "mcpServers": {
    "vulnerable-mcp-server-outdated-pacakges": {
      "command": "node",
      "args": [
        "/absolute/path/to/vulnerable-mcp-server-outdated-pacakges/index.js"
      ]
    }
  }
}

5. Restart Claude so it loads the updated MCP configuration.

After Claude restarts, the server should appear as:

• vulnerable-mcp-server-outdated-pacakges

Run manually (for debugging)

This server speaks MCP over stdio (JSON-RPC over stdin/stdout). Most users should run it via an MCP-capable client (like Claude) rather than manually.

If you just want to confirm it starts:

npm install
node index.js

Example usage (tools)

From your MCP client, call tools like these:

• Get OS/system info:
  • get_system_info
• List a directory:
  • list_directory with path: "/tmp"
• Check if a path exists:
  • check_path_exists with path: "/etc/passwd"
• Get file stats:
  • get_file_stats with path: "/etc/hosts"
• Calculate a folder size:
  • get_folder_size with path: "/var/log"

Notes

• To surface the intentionally vulnerable dependency set:

npm audit

• You can also inspect the dependency tree:

npm ls

Links to Appsecco Resources

• Appsecco LinkedIn
• Appsecco YouTube
• Appsecco Website