Turbo Intruder JSON Fuzzing Example using JSONAccessor

json_fuzz_poc.py

# JSON Fuzz Proof of Concept using JSONAccessor
# Author: Evan Custodio (@defparam)
#
# MIT License
# Copyright 2021 Evan Custodio
#
# Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
#
# The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
import json
from copy import deepcopy
import random

def queueRequests(target, wordlists):
    engine = RequestEngine(endpoint=target.endpoint)
    
    # Take the request and parse it into a headers + body (assuming JSON body)
    headers, body = JSONAccessor.parse_into_parts(target.req)
    
    # Create a JSONAccessor Object
    JA = JSONAccessor(body)
    
    # Iterate through each value/index in the JSON
    for JSON_Value, JSON_Index in JA:
        JA.initialize() # Call initialize to reset the internal JSON structure
        
        # If the value type is a string, append a quote mark
        if type(JSON_Value) == str:
           JA[JSON_Index] = JSON_Value + "'"
           
        # If the value type is an int, change it to -1
        if type(JSON_Value) == int:
           JA[JSON_Index] = -1
           
        # Build an HTTP request with the mutated JSON providing the headers
        test_request = JA.request(headers)
        
        # Send out the test
        engine.queue(test_request)


def handleResponse(req, interesting):
    table.add(req)



# The JSONAccessor Class
#
# This class is the main JSON Parser which parses input JSON and provides
# the ability to access and modify a JSON structure as a flat list or iterator
class JSONAccessor:
    def __init__(self, content):
        self._d = json.loads(content)
        self._d_initial = deepcopy(self._d)
        self._i = 0
        self._ind = 0
        self._getval = None
        self._size = self._countdict(self._d)
        
    @staticmethod
    def parse_into_parts(request):
        tokens = request.split('\r\n\r\n')
        headers = tokens[0]
        body = ('\r\n\r\n').join(tokens[1:])
        return (headers, body,)
        
    def request(self, headers):
        return headers + "\r\n\r\n" + str(self)
        
    def initialize(self):
        self._d = deepcopy(self._d_initial)
        
    def _iterlist(self,l,ind,set=None):
        for x in range(len(l)):
            item = l[x]
            if type(item) == dict:
                self._iterdict(item,ind,set)
            elif type(item) == list:
                self._iterlist(item,ind,set)
            else:
                if self._i == ind:
                    self._getval = item
                    if set != None:
                        l[x] = set
                self._i += 1
                    
            if self._getval != None:
                return
        
    def _iterdict(self,d,ind,set=None):
        for key in d.keys():
            item = d[key]
            if type(item) == dict:
                self._iterdict(item,ind,set)
            elif type(item) == list:
                self._iterlist(item,ind,set)
            else:
                if self._i == ind:
                    self._getval = item
                    if set != None:
                        d[key] = set
                self._i += 1
                    
            if self._getval != None:
                return
            
    def _countlist(self,l):
        for item in l:
            if type(item) == dict:
                self._countdict(item)
            elif type(item) == list:
                self._countlist(item)
            else:
                self._i += 1
            
    def _countdict(self,d):
        for key in d.keys():
            item = d[key]
            if type(item) == dict:
                self._countdict(item)
            elif type(item) == list:
                self._countlist(item)
            else:
                self._i += 1
        return self._i
        
    def __iter__(self):
        self._ind = 0
        return self
        
    def next(self):
        if self._ind == len(self):
            raise StopIteration
        else:
            ret = self[self._ind], self._ind
            self._ind += 1
            return ret
            
    def __len__(self):
        return self._size
        
    def __repr__(self):
        return str(self._d)
        
    def __setitem__(self, key, value):
        self._i = 0
        self._getval = None
        self._iterdict(self._d, key, value)       
        
    def __getitem__(self, key):
        self._i = 0
        self._getval = None
        self._iterdict(self._d, key)
        return self._getval
        
    def __str__(self):
        return json.dumps(self._d)