PyJFuzz is a small, extensible and ready-to-use framework used to fuzz JSON inputs, such as mobile endpoint REST API, JSON implementation, Browsers, cli executable and much more.

Note:

This fork of PyJFuzz was made python3 compatible with minimal effort

Changes

• 2to3 for (basic) python3 support
• Disabled pjf.log file ..

Installation

You can install PyJFuzz with the following command

sudo -EH pip3 install gramfuzz bottle netifaces gitpython
git clone https://github.com/0xricksanchez/PyJFuzz.git && cd PyJFuzz && sudo -EH python3 setup.py install

Usage:

Classes

The available object/class are the following:

• PJFServer - User to start and stop built-in HTTP and HTTPS servers
• PJFProcessMonitor - Used to monitor process crash, it will automatically restart proccess each time it crash
• PJFTestcaseServer - The testcase server is used in conjunction with PJFProcessMonitor, whenever a process crash the testcase server will register and store the JSON which cause the crash
• PJFFactory - It's the main object used to do the real fuzz of JSON objects
• PJFConfiguration - It's the configuration file for each of the available objects
• PJFExternalFuzzer - Used by PJFactory is a auxiliary class which provide an interface to other command line fuzzer such as radamsa
• PJFMutation - Used by PJFFactory provide all the mutation used during fuzzing session
• PJFExecutor - Provides an interface to interact with external process

Examples

# simple_fuzzer

from pyjfuzz.core.pjf_configuration import PJFConfiguration
from pyjfuzz.core.pjf_factory import PJFFactory
from argparse import Namespace

config = PJFConfiguration(Namespace(json={"test": ["1", 2, True]}, nologo=True, level=6, techniques="P"))
# once a config object is defined you can access to config.techniques to view the selected techniques for your group
# print("Techniques IDs: {0}".format(str(config.techniques)))
# you can eventually modify them!
# config.techniques = [2]
# This way only attack number 2 (LFI Attack) will be performed!
fuzzer = PJFFactory(config)
while True:
    print(fuzzer.fuzzed)

Configuration table

Name	Type	Description
json	dict	JSON object to fuzz
json_file	str	Path to a JSON file
parameters	list<str>	List of parameters to fuzz (taken from JSON object)
techniques	str<int>	String of enable attacks, used to generate fuzzed JSON, such as XSS, LFI etc. ie "CHPTRSX" (Look techniques table)
level	int	Fuzzing level in the range 0-6
utf8	bool	If true switch from unicode encode to pure byte representation
indent	bool	Set whenever to indent the result object
url_encode	bool	Set whenever to URLEncode the result object
strong_fuzz	bool	Set whenever to use strong fuzzing (strong fuzzing will not maintain JSON structure, usefull for parser fuzzing)
debug	bool	Set whenever to enable debug prints
exclude	bool	Exclude from fuzzing parameters selected by parameters option
notify	bool	Set whenever to notify process monitor when a crash occurs only used with PJFServer
html	str	Path to an HTML directory to serve within PJFServer
ext_fuzz	bool	Set whenever to use binary from "command" as an externale fuzzer
cmd_fuzz	bool	Set whenever to use binary from "command" as fuzzer target
content_type	str	Set the content type result of PJFServer (default application/json)
command	list<str>	Command to execute each paramester is a list element, you could use shlex.split from python

Techniques table

Index	Description
0	XSS injection (Polyglot)
1	SQL injection (Polyglot)
2	LFI attack
3	SQL injection polyglot (2)
4	XSS injection (Polyglot) (2)
5	RCE injection (Polyglot)
6	LFI attack (2)
7	Data URI attack
8	LFI and HREF attack
9	Header injection
10	RCE injection (Polyglot) (2)
11	Generic templace injection
12	Flask template injection
13	Random character attack

techniques = {
                "C": [10, 5, 13],
                "H": [9],
                "P": [6, 2, 8],
                "T": [11, 12],
                "R": [14],
                "S": [3, 1],
                "X": [0, 4, 7]
            }

Issues

Please send any issue here via GitHub I'll provide a fix as soon as possible.

Result

Below a list of know issue found by PyJFuzz, the list will be updated weekly

• Double free in cJSON (DaveGamble/cJSON#105)
• Unhandled exception in picojson (kazuho/picojson#94)
• Memory leak in simpleJSON (nbsdx/SimpleJSON#8)
• Stack base buffer overflow in frozen (cesanta/frozen#14)
• Memory corruption with custom EIP (cesanta/frozen#15)