Land rapid7#19115, read/write registry key SD

Module to read/write registry key security descriptor remotely

documentation/modules/auxiliary/admin/registry_security_descriptor.md

@@ -0,0 +1,84 @@
+## Vulnerable Application
+
+This module reads or writes a Windows registry security descriptor remotely.
+
+In READ mode, the `FILE` option can be set to specify where the security
+descriptor should be written to.
+
+The following format is used:
+```
+key: <registry key>
+security_info: <security information>
+sd: <security descriptor as a hex string>
+```
+
+In WRITE mode, the `FILE` option can be used to specify the information needed
+to write the security descriptor to the remote registry. The file must follow
+the same format as described above.
+
+## Verification Steps
+
+1. Start msfconsole
+1. Do: `use auxiliary/admin/registry_security_descriptor`
+1. Do: `run verbose=true rhost=<host> smbuser=<username> smbpass=<password> key=<registry key>`
+1. **Verify** the registry key security descriptor is displayed
+1. Do: `run verbose=true rhost=<host> smbuser=<username> smbpass=<password> key=<registry key> file=<file path>`
+1. **Verify** the registry key security descriptor is saved to the file
+1. Do: `run verbose=true rhost=<host> smbuser=<username> smbpass=<password> key=<registry key> action=write sd=<security descriptor as a hex string>`
+1. **Verify** the security descriptor is correctly set on the given registry key
+1. Do: `run verbose=true rhost=<host> smbuser=<username> smbpass=<password> file=<file path>`
+1. **Verify** the security descriptor taken from the file is correctly set on the given registry key
+
+## Options
+
+### KEY
+Registry key to read or write.
+
+### SD
+Security Descriptor to write as a hex string.
+
+### SECURITY_INFORMATION
+Security Information to read or write (see
+https://learn.microsoft.com/en-us/openspecs/windows_protocols/ms-dtyp/23e75ca3-98fd-4396-84e5-86cd9d40d343
+(default: OWNER_SECURITY_INFORMATION | GROUP_SECURITY_INFORMATION | DACL_SECURITY_INFORMATION).
+
+### FILE
+File path to store the security descriptor when reading or source file path used to write the security descriptor when writing
+
+
+## Scenarios
+
+### Read against Windows Server 2019
+
+```
+msf6 auxiliary(admin/registry_security_descriptor) > run verbose=true rhost=192.168.101.124 smbuser=Administrator smbpass=123456 action=READ key='HKLM\SECURITY\Policy\PolEKList'
+[*] Running module against 192.168.101.124
+
+[+] 192.168.101.124:445 - Raw security descriptor for HKLM\SECURITY\Policy\PolEKList: 01000480480000005800000000000000140000000200340002000000000214003f000f0001010000000000051200000000021800000006000102000000000005200000002002000001020000000000052000000020020000010100000000000512000000
+[*] Auxiliary module execution completed
+```
+
+### Write against Windows Server 2019
+Note that the information security has been set to 4 (DACL_SECURITY_INFORMATION) to avoid an access denied error.
+
+```
+msf6 auxiliary(admin/registry_security_descriptor) > run verbose=true rhost=192.168.101.124 smbuser=Administrator smbpass=123456 key='HKLM\SECURITY\Policy\PolEKList' action=WRITE sd=01000480480000005800000000000000140000000200340002000000000214003f000f0001010000000000051200000000021800000006000102000000000005200000002002000001020000000000052000000020020000010100000000000512000000 security_information=4
+[*] Running module against 192.168.101.124
+
+[+] 192.168.101.124:445 - Security descriptor set for HKLM\SECURITY\Policy\PolEKList
+[*] Auxiliary module execution completed
+```
+
+### Write against Windows Server 2019 (from file)
+
+```
+msf6 auxiliary(admin/registry_security_descriptor) > run verbose=true rhost=192.168.101.124 smbuser=Administrator smbpass=123456 action=WRITE file=/tmp/remote_registry_sd_backup.yml
+[*] Running module against 192.168.101.124
+
+[*] 192.168.101.124:445 - Getting security descriptor info from file /tmp/remote_registry_sd_backup.yml
+  key: HKLM\SECURITY\Policy\PolEKList
+  security information: 4
+  security descriptor: 01000480480000005800000000000000140000000200340002000000000214003f000f0001010000000000051200000000021800000006000102000000000005200000002002000001020000000000052000000020020000010100000000000512000000
+[+] 192.168.101.124:445 - Security descriptor set for HKLM\SECURITY\Policy\PolEKList
+[*] Auxiliary module execution completed
+```

modules/auxiliary/admin/registry_security_descriptor.rb

@@ -0,0 +1,168 @@
+##
+# This module requires Metasploit: https://metasploit.com/download
+# Current source: https://github.com/rapid7/metasploit-framework
+##
+
+class MetasploitModule < Msf::Auxiliary
+  include Msf::Exploit::Remote::SMB::Client::Authenticated
+  include Msf::OptionalSession::SMB
+  include Msf::Util::WindowsRegistry
+
+  def initialize(info = {})
+    super(
+      update_info(
+        info,
+        'Name' => 'Windows Registry Security Descriptor Utility',
+        'Description' => %q{
+          Read or write a Windows registry security descriptor remotely.
+
+          In READ mode, the `FILE` option can be set to specify where the
+          security descriptor should be written to.
+
+          The following format is used:
+          ```
+          key: <registry key>
+          security_info: <security information>
+          sd: <security descriptor as a hex string>
+          ```
+
+          In WRITE mode, the `FILE` option can be used to specify the information
+          needed to write the security descriptor to the remote registry. The file must
+          follow the same format as described above.
+        },
+        'Author' => [
+          'Christophe De La Fuente'
+        ],
+        'License' => MSF_LICENSE,
+        'Actions' => [
+          [ 'READ', { 'Description' => 'Read a Windows registry security descriptor' } ],
+          [ 'WRITE', { 'Description' => 'Write a Windows registry security descriptor' } ]
+        ],
+        'Notes' => {
+          'Stability' => [CRASH_SAFE],
+          'Reliability' => [],
+          'SideEffects' => [CONFIG_CHANGES]
+        },
+        'DefaultAction' => 'READ'
+      )
+    )
+
+    register_options(
+      [
+        OptString.new('KEY', [ false, 'Registry key to read or write' ]),
+        OptString.new('SD', [ false, 'Security Descriptor to write as a hex string' ], conditions: %w[ACTION == WRITE], regex: /^([a-fA-F0-9]{2})+$/),
+        OptInt.new('SECURITY_INFORMATION', [
+          true,
+          'Security Information to read or write (see '\
+          'https://learn.microsoft.com/en-us/openspecs/windows_protocols/ms-dtyp/23e75ca3-98fd-4396-84e5-86cd9d40d343 '\
+          '(default: OWNER_SECURITY_INFORMATION | GROUP_SECURITY_INFORMATION | DACL_SECURITY_INFORMATION)',
+          RubySMB::Field::SecurityDescriptor::OWNER_SECURITY_INFORMATION |
+            RubySMB::Field::SecurityDescriptor::GROUP_SECURITY_INFORMATION |
+            RubySMB::Field::SecurityDescriptor::DACL_SECURITY_INFORMATION
+        ]),
+        OptString.new('FILE', [
+          false,
+          'File path to store the security descriptor when reading or source file path used to write the security descriptor when writing'
+        ])
+      ]
+    )
+  end
+
+  def do_connect
+    if session
+      print_status("Using existing session #{session.sid}")
+      client = session.client
+      self.simple = ::Rex::Proto::SMB::SimpleClient.new(client.dispatcher.tcp_socket, client: client)
+      simple.connect("\\\\#{simple.address}\\IPC$")
+    else
+      connect
+      begin
+        smb_login
+      rescue Rex::Proto::SMB::Exceptions::Error, RubySMB::Error::RubySMBError => e
+        fail_with(Module::Failure::NoAccess, "Unable to authenticate ([#{e.class}] #{e}).")
+      end
+    end
+
+    report_service(
+      host: simple.address,
+      port: simple.port,
+      host_name: simple.client.default_name,
+      proto: 'tcp',
+      name: 'smb',
+      info: "Module: #{fullname}, last negotiated version: SMBv#{simple.client.negotiated_smb_version} (dialect = #{simple.client.dialect})"
+    )
+
+    begin
+      @tree = simple.client.tree_connect("\\\\#{simple.address}\\IPC$")
+    rescue RubySMB::Error::RubySMBError => e
+      fail_with(Module::Failure::Unreachable, "Unable to connect to the remote IPC$ share ([#{e.class}] #{e}).")
+    end
+
+    begin
+      @winreg = @tree.open_file(filename: 'winreg', write: true, read: true)
+      @winreg.bind(endpoint: RubySMB::Dcerpc::Winreg)
+    rescue RubySMB::Error::RubySMBError => e
+      fail_with(Module::Failure::Unreachable, "Error when connecting to 'winreg' interface ([#{e.class}] #{e}).")
+    end
+  end
+
+  def run
+    do_connect
+
+    case action.name
+    when 'READ'
+      action_read
+    when 'WRITE'
+      action_write
+    else
+      print_error("Unknown action #{action.name}")
+    end
+  ensure
+    @winreg.close if @winreg
+    @tree.disconnect! if @tree
+    # Don't disconnect the client if it's coming from the session so it can be reused
+    unless session
+      simple.client.disconnect! if simple&.client.is_a?(RubySMB::Client)
+      disconnect
+    end
+  end
+
+  def action_read
+    fail_with(Failure::BadConfig, 'Unknown registry key, please set the `KEY` option') if datastore['KEY'].blank?
+
+    sd = @winreg.get_key_security_descriptor(datastore['KEY'], datastore['SECURITY_INFORMATION'], bind: false)
+    print_good("Raw security descriptor for #{datastore['KEY']}: #{sd.bytes.map { |c| '%02x' % c.ord }.join}")
+
+    unless datastore['FILE'].blank?
+      remote_reg = Msf::Util::WindowsRegistry::RemoteRegistry.new(@winreg, name: :sam)
+      remote_reg.save_to_file(datastore['KEY'], sd, datastore['SECURITY_INFORMATION'], datastore['FILE'])
+      print_good("Saved to file #{datastore['FILE']}")
+    end
+  end
+
+  def action_write
+    if datastore['FILE'].blank?
+      fail_with(Failure::BadConfig, 'Unknown security descriptor, please set the `SD` option') if datastore['SD'].blank?
+      fail_with(Failure::BadConfig, 'Unknown registry key, please set the `KEY` option') if datastore['KEY'].blank?
+      sd = datastore['SD']
+      key = datastore['KEY']
+      security_info = datastore['SECURITY_INFORMATION']
+    else
+      print_status("Getting security descriptor info from file #{datastore['FILE']}")
+      remote_reg = Msf::Util::WindowsRegistry::RemoteRegistry.new(@winreg, name: :sam)
+      sd_info = remote_reg.read_from_file(datastore['FILE'])
+      sd = sd_info['sd']
+      key = sd_info['key']
+      security_info = sd_info['security_info']
+      vprint_line("  key: #{key}")
+      vprint_line("  security information: #{security_info}")
+      vprint_line("  security descriptor: #{sd}")
+    end
+
+    sd = sd.chars.each_slice(2).map { |c| c.join.to_i(16).chr }.join
+    @winreg.set_key_security_descriptor(key, sd, security_info, bind: false)
+    print_good("Security descriptor set for #{key}")
+  rescue RubySMB::Dcerpc::Error::WinregError => e
+    fail_with(Failure::Unknown, "Unable to set the security descriptor for #{key}: #{e}")
+  end
+end

modules/auxiliary/example.rb

@@ -42,12 +42,9 @@ def run
     print_status("Running the simple auxiliary module with action #{action.name}")
   end
 
-  # auxiliary modules can register new commands, they all call cmd_* to
-  # dispatch them
-  def auxiliary_commands
-    { 'aux_extra_command' => 'Run this auxiliary test commmand' }
-  end
-
+  # Framework automatically registers `cmd_*` methods to be dispatched when the
+  # corresponding command is used. For example, here this method will be called
+  # when entering the `aux_extra_command` command in the console.
   def cmd_aux_extra_command(*args)
     print_status("Running inside aux_extra_command(#{args.join(' ')})")
   end