ProtoBurp

Check out my blog post detailing the wonderful things you can do with ProtoBurp! https://dillonfrankesecurity.com/posts/protoburp-encode-custom-protobuf-messages-in-burp/

Description

ProtoBurp is a Burp Suite extension that enables security researchers to encode and fuzz custom Protobuf messages. It allows users to automatically convert JSON data into a Protobuf message based on a provided protobuf definition file. This opens up opportunities for fuzzing inputs using Burp's Repeater and Intruder tools, as well as proxy traffic from other tools (e.g. sqlmap).

Installation

1. Clone the ProtoBurp repository and its submodules

git clone --recursive https://github.com/dillonfranke/protoburp.git

Make sure to add the --recursive option

2. Install the protoc utility, which you'll need to compile Protobuf defintion (.proto) files

Mac:

brew install protobuf

Debian Linux:

sudo apt-get update
sudo apt-get install protobuf-compiler

Windows: https://github.com/protocolbuffers/protobuf/releases

3. Run the setup.sh script

This will install Google's protobuf module so it can be used by the extension

sudo ./setup.sh

Usage

1. Compile the .proto file you want to convert into Python format

Several example .proto files are contained in the test_app folder

protoc --python_out=. addressbook.proto

2. Load the ProtoBurp extension and select your compiled .proto file

• Click 'Enable ProtoBurp'
• Select the Python Protobuf definition file you just compiled

3. Set the ProtoBurp header on your requests, and your requests will be transformed from JSON to Protobuf!

Generating a JSON payload

You might be wondering: "How can I generate a JSON object from a .proto file to use with ProtoBurp?"

Easy, I wrote a script that, given a .proto file, will fill in placeholder values to generate a JSON payload. You can then use the JSON payload with ProtoBurp. Here's how you use the script:

❯ python3 json-generator.py
Usage: python3 json-generator.py <compiled_proto_definition_pb2.py> <MessageName>

❯ python3 json-generator.py test_app/addressbook_pb2.py AddressBook
{
  "people": [
    {
      "name": "example",
      "id": 1,
      "email": "example",
      "phones": [
        {
          "number": "example",
          "type": "PHONE_TYPE_UNSPECIFIED"
        },
        {
          "number": "example",
          "type": "PHONE_TYPE_UNSPECIFIED"
        }
      ]
    },
    {
      "name": "example",
      "id": 1,
      "email": "example",
      "phones": [
        {
          "number": "example",
          "type": "PHONE_TYPE_UNSPECIFIED"
        },
        {
          "number": "example",
          "type": "PHONE_TYPE_UNSPECIFIED"
        }
      ]
    }
  ]
}

Use Cases

Please see my blog post, where I talk about how you can use ProtoBurp with Repeater, Intruder, and external security utilities like sqlmap!

Bugs and Feature Requests

Please use the issues tab for any bugs or feature requests.

Happy Hunting!