MCPwned

MCPwned

One-line summary : Companion extension for pwning MCP servers

Detailed description :

MCPwned is a companion extension that enables pentesters to effectively test MCP servers. It recognizes MCP-like endpoints, provides a scanner and a tree-like display of capabilities, as well as a template request for each capability. It also provides quality of life features such as response extracting and session ID refresh.

Basic Usage

Whenever you encounter an MCP-like endpoint the extension will color it in gray. From there you can send the request to the extension with a right-click or a Ctrl + M shortcut. You can among others :

• Send a capability usage template to the repeater (also supports completion)
• Annotate/color capabilities to stay organized
• Refresh session ID from the repeater or the extension tab
• Export your findings in Markdown

Please find below the other features ;)

Features (Roadmap)

Scanning & Auditing

• The extension provides a scanner for :
  • Tools
  • Prompts
  • Resources
    • + resource template
• Debug mode configurable from settings
• Configurable logging of the request in the logger tab or at least some way to see the queries being made
• pulls session id in server data based on the URL
• Autodetects MCP-like exchanges in proxy

Attacking

• Enables to send a request to the repeater
  • Attaches the session ID properly
  • Provides a way of retrieving new session IDs automatically
• Provides a way to test completion to leak valid resource URIs and argument values the server accepts
• pulls session id in repeater based on the URL
• Shows responses in a nice readable format

QOL

• Shortcuts :
  • Ctrl + M → sends to extension
  • Ctrl + Shift + M → move to extension page
• display nicely
  • show in tree form
  • displays the tool/resource/prompt information
  • combine/merge all data from the same URL and updates accordingly
  • Show error in case of error at MCP connection level
  • Delete entries

Reporting and Organizing

• Change server name
• Set leaf color
• Add notes
• Export to Markdown

Bugs to fix

• Hangs on HTTPStreambuilder
• Color bug in tree
• Session ID being invalidated when SDK sends DELETE
• Scan with ... Not working from repeater and other pane-based tabs
• Send to repeater does not properly focus the new tab
• Foreground color does not update properly on leaves leaving white on white sometimes
• Tree sometimes showing up weird when reloading project
• \n not handled properly in the right panel when used in description
• Server data display does not refresh upon session refresh

BApp Store acceptance criteria

• It performs a unique function.
• It has a clear, descriptive name
• It operates securely.
• It includes all dependencies.
• It uses threads to maintain responsiveness.
• It unloads cleanly.
• It uses Burp networking.
  • Still uses io.modelcontextprotocol.sdk:mcp for probing due to no better solution for now
• It supports offline working.
• It can cope with large projects.
• It provides a parent for GUI elements.
• It uses the Montoya API artifact.
• It uses Burp AI as the default AI provider