Module: Rex::Proto::MSSQL::ClientMixin

Extended by:
Forwardable
Includes:
Msf::Module::UI::Message
Included in:
Client
Defined in:
lib/rex/proto/mssql/client_mixin.rb

Overview

A base mixin of useful mssql methods for parsing structures etc

Defined Under Namespace

Modules: ENVCHANGE

Constant Summary collapse

ENCRYPT_OFF =

Encryption

0x00
ENCRYPT_ON =

Encryption is available but off.

0x01
ENCRYPT_NOT_SUP =

Encryption is available and on.

0x02
ENCRYPT_REQ =

Encryption is not available.

0x03
TYPE_SQL_BATCH =

Packet Type

1
TYPE_PRE_TDS7_LOGIN =

(Client) SQL command

2
TYPE_RPC =

(Client) Pre-login with version < 7 (unused)

3
TYPE_TABLE_RESPONSE =

(Client) RPC

4
TYPE_ATTENTION_SIGNAL =

Request Completion, Error and Info Messages, Attention Acknowledgement

6
TYPE_BULK_LOAD =

(Client) Attention

7
TYPE_TRANSACTION_MANAGER_REQUEST =

(Client) SQL Command with binary data

14
TYPE_TDS7_LOGIN =

(Client) Transaction request manager

16
TYPE_SSPI_MESSAGE =

(Client) Login

17
TYPE_PRE_LOGIN_MESSAGE =

(Client) Login

18
STATUS_NORMAL =

Status

0x00
STATUS_END_OF_MESSAGE = 
0x01
STATUS_IGNORE_EVENT = 
0x02
STATUS_RESETCONNECTION =

TDS 7.1+

0x08
STATUS_RESETCONNECTIONSKIPTRAN =

TDS 7.3+

0x10

Instance Method Summary collapse

Methods included from Msf::Module::UI::Message

#print_error, #print_good, #print_prefix, #print_status, #print_warning

Methods included from Msf::Module::UI::Message::Verbose

#vprint_error, #vprint_good, #vprint_status, #vprint_warning

Instance Method Details

#mssql_parse_done(data, info) ⇒ Object

Parse a “done” TDS token



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# File 'lib/rex/proto/mssql/client_mixin.rb', line 633

def mssql_parse_done(data, info)
  status, cmd, rows = data.slice!(0, 8).unpack('vvV')
  info[:done] = { :status => status, :cmd => cmd, :rows => rows }
  info
end

#mssql_parse_env(data, info) ⇒ Object

Parse an “environment change” TDS token



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# File 'lib/rex/proto/mssql/client_mixin.rb', line 657

def mssql_parse_env(data, info)
  len  = data.slice!(0, 2).unpack('v')[0]
  buff = data.slice!(0, len)
  type = buff.slice!(0, 1).unpack('C')[0]

  nval = ''
  nlen = buff.slice!(0, 1).unpack('C')[0] || 0
  nval = buff.slice!(0, nlen * 2).gsub("\x00", '') if nlen > 0

  oval = ''
  olen = buff.slice!(0, 1).unpack('C')[0] || 0
  oval = buff.slice!(0, olen * 2).gsub("\x00", '') if olen > 0

  info[:envs] ||= []
  info[:envs] << { :type => type, :old => oval, :new => nval }

  self.current_database = nval if type == ENVCHANGE::DATABASE

  info
end

#mssql_parse_error(data, info) ⇒ Object

Parse an “error” TDS token



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# File 'lib/rex/proto/mssql/client_mixin.rb', line 642

def mssql_parse_error(data, info)
  len  = data.slice!(0, 2).unpack('v')[0]
  buff = data.slice!(0, len)

  errno, state, sev, elen = buff.slice!(0, 8).unpack('VCCv')
  emsg = buff.slice!(0, elen * 2)
  emsg.gsub!("\x00", '')

  info[:errors] << "SQL Server Error ##{errno} (State:#{state} Severity:#{sev}): #{emsg}"
  info
end

#mssql_parse_info(data, info) ⇒ Object

Parse an “information” TDS token



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# File 'lib/rex/proto/mssql/client_mixin.rb', line 681

def mssql_parse_info(data, info)
  len  = data.slice!(0, 2).unpack('v')[0]
  buff = data.slice!(0, len)

  errno, state, sev, elen = buff.slice!(0, 8).unpack('VCCv')
  emsg = buff.slice!(0, elen * 2)
  emsg.gsub!("\x00", '')

  info[:infos] ||= []
  info[:infos] << "SQL Server Info ##{errno} (State:#{state} Severity:#{sev}): #{emsg}"
  info
end

#mssql_parse_login_ack(data, info) ⇒ Object

Parse a “login ack” TDS token



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# File 'lib/rex/proto/mssql/client_mixin.rb', line 697

def (data, info)
  len = data.slice!(0, 2).unpack('v')[0]
  _buff = data.slice!(0, len)
  info[:login_ack] = true
end

#mssql_parse_reply(data, info) ⇒ Object

Parse individual tokens from a TDS reply



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# File 'lib/rex/proto/mssql/client_mixin.rb', line 385

def mssql_parse_reply(data, info)
  info[:errors] = []
  return if not data
  states = []
  until data.empty? || info[:errors].any?
    token = data.slice!(0, 1).unpack('C')[0]
    case token
    when 0x81
      states << :mssql_parse_tds_reply
      mssql_parse_tds_reply(data, info)
    when 0xd1
      states << :mssql_parse_tds_row
      mssql_parse_tds_row(data, info)
    when 0xe3
      states << :mssql_parse_env
      mssql_parse_env(data, info)
    when 0x79
      states << :mssql_parse_ret
      mssql_parse_ret(data, info)
    when 0xfd, 0xfe, 0xff
      states << :mssql_parse_done
      mssql_parse_done(data, info)
    when 0xad
      states << :mssql_parse_login_ack
      (data, info)
    when 0xab
      states << :mssql_parse_info
      mssql_parse_info(data, info)
    when 0xaa
      states << :mssql_parse_error
      mssql_parse_error(data, info)
    when nil
      break
    else
      info[:errors] << "unsupported token: #{token}. Previous states: #{states}"
      break
    end
  end
  info
end

#mssql_parse_ret(data, info) ⇒ Object

Parse a “ret” TDS token



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# File 'lib/rex/proto/mssql/client_mixin.rb', line 624

def mssql_parse_ret(data, info)
  ret = data.slice!(0, 4).unpack('N')[0]
  info[:ret] = ret
  info
end

#mssql_parse_tds_reply(data, info) ⇒ Object

Parse a raw TDS reply from the server



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# File 'lib/rex/proto/mssql/client_mixin.rb', line 246

def mssql_parse_tds_reply(data, info)
  info[:errors] ||= []
  info[:colinfos] ||= []
  info[:colnames] ||= []

  # Parse out the columns
  cols = data.slice!(0, 2).unpack('v')[0]
  0.upto(cols-1) do |col_idx|
    col = {}
    info[:colinfos][col_idx] = col

    col[:utype] = data.slice!(0, 2).unpack('v')[0]
    col[:flags] = data.slice!(0, 2).unpack('v')[0]
    col[:type]  = data.slice!(0, 1).unpack('C')[0]
    case col[:type]
    when 48
      col[:id] = :tinyint

    when 52
      col[:id] = :smallint

    when 56
      col[:id] = :rawint

    when 61
      col[:id] = :datetime

    when 34
      col[:id]            = :image
      col[:max_size]      = data.slice!(0, 4).unpack('V')[0]
      col[:value_length]  = data.slice!(0, 2).unpack('v')[0]
      col[:value]         = data.slice!(0, col[:value_length]  * 2).gsub("\x00", '')

    when 109
      col[:id] = :float
      col[:value_length] = data.slice!(0, 1).unpack('C')[0]

    when 108
      col[:id] = :numeric
      col[:value_length] = data.slice!(0, 1).unpack('C')[0]
      col[:precision] = data.slice!(0, 1).unpack('C')[0]
      col[:scale] = data.slice!(0, 1).unpack('C')[0]

    when 60
      col[:id] = :money

    when 110
      col[:value_length] = data.slice!(0, 1).unpack('C')[0]
      case col[:value_length]
      when 8
        col[:id] = :money
      when 4
        col[:id] = :smallmoney
      else
        col[:id] = :unknown
      end

    when 111
      col[:value_length] = data.slice!(0, 1).unpack('C')[0]
      case col[:value_length]
      when 4
        col[:id] = :smalldatetime
      when 8
        col[:id] = :datetime
      else
        col[:id] = :unknown
      end

    when 122
      col[:id] = :smallmoney

    when 59
      col[:id] = :float

    when 58
      col[:id] = :smalldatetime

    when 36
      col[:id] = :guid
      col[:value_length] = data.slice!(0, 1).unpack('C')[0]

    when 38
      col[:id] = :int
      col[:int_size] = data.slice!(0, 1).unpack('C')[0]

    when 50
      col[:id] = :bit

    when 99
      col[:id] = :ntext
      col[:max_size] = data.slice!(0, 4).unpack('V')[0]
      col[:codepage] = data.slice!(0, 2).unpack('v')[0]
      col[:cflags] = data.slice!(0, 2).unpack('v')[0]
      col[:charset_id] =  data.slice!(0, 1).unpack('C')[0]
      col[:namelen] = data.slice!(0, 1).unpack('C')[0]
      col[:table_name] = data.slice!(0, (col[:namelen] * 2) + 1).gsub("\x00", '')

    when 104
      col[:id] = :bitn
      col[:int_size] = data.slice!(0, 1).unpack('C')[0]

    when 127
      col[:id] = :bigint

    when 165
      col[:id] = :hex
      col[:max_size] = data.slice!(0, 2).unpack('v')[0]

    when 173
      col[:id] = :hex # binary(2)
      col[:max_size] = data.slice!(0, 2).unpack('v')[0]

    when 231, 175, 167, 239
      col[:id] = :string
      col[:max_size] = data.slice!(0, 2).unpack('v')[0]
      col[:codepage] = data.slice!(0, 2).unpack('v')[0]
      col[:cflags] = data.slice!(0, 2).unpack('v')[0]
      col[:charset_id] =  data.slice!(0, 1).unpack('C')[0]

    else
      col[:id] = :unknown

      # See https://learn.microsoft.com/en-us/openspecs/windows_protocols/ms-tds/ce3183a6-9d89-47e8-a02f-de5a1a1303de for details about column types
      info[:errors] << "Unsupported column type: #{col[:type]}. "
      return info
    end

    col[:msg_len] = data.slice!(0, 1).unpack('C')[0]

    if col[:msg_len] && col[:msg_len] > 0
      col[:name] = data.slice!(0, col[:msg_len] * 2).gsub("\x00", '')
    end
    info[:colnames] << (col[:name] || 'NULL')
  end
end

#mssql_parse_tds_row(data, info) ⇒ Object

Parse a single row of a TDS reply



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# File 'lib/rex/proto/mssql/client_mixin.rb', line 429

def mssql_parse_tds_row(data, info)
  info[:rows] ||= []
  row = []

  info[:colinfos].each do |col|

    if(data.length == 0)
      row << "<EMPTY>"
      next
    end

    case col[:id]
    when :hex
      str = ""
      len = data.slice!(0, 2).unpack('v')[0]
      if len > 0 && len < 65535
        str << data.slice!(0, len)
      end
      row << str.unpack("H*")[0]

    when :guid
      read_length = data.slice!(0, 1).unpack1('C')
      if read_length == 0
        row << nil
      else
        row << Rex::Text.to_guid(data.slice!(0, read_length))
      end

    when :string
      str = ""
      len = data.slice!(0, 2).unpack('v')[0]
      if len > 0 && len < 65535
        str << data.slice!(0, len)
      end
      row << str.gsub("\x00", '')

    when :ntext
      str = nil
      ptrlen = data.slice!(0, 1).unpack("C")[0]
      ptr = data.slice!(0, ptrlen)
      unless ptrlen == 0
        timestamp = data.slice!(0, 8)
        datalen = data.slice!(0, 4).unpack("V")[0]
        if datalen > 0 && datalen < 65535
          str = data.slice!(0, datalen).gsub("\x00", '')
        else
          str = ''
        end
      end
      row << str

    when :float
      datalen = data.slice!(0, 1).unpack('C')[0]
      case datalen
      when 8
        row << data.slice!(0, datalen).unpack('E')[0]
      when 4
        row << data.slice!(0, datalen).unpack('e')[0]
      else
        row << nil
      end

    when :numeric
      varlen = data.slice!(0, 1).unpack('C')[0]
      if varlen == 0
        row << nil
      else
        sign = data.slice!(0, 1).unpack('C')[0]
        raw = data.slice!(0, varlen - 1)
        value = ''

        case varlen
        when 5
          value = raw.unpack('L')[0]/(10**col[:scale]).to_f
        when 9
          value = raw.unpack('Q')[0]/(10**col[:scale]).to_f
        when 13
          chunks = raw.unpack('L3')
          value = chunks[2] << 64 | chunks[1] << 32 | chunks[0]
          value /= (10**col[:scale]).to_f
        when 17
          chunks = raw.unpack('L4')
          value = chunks[3] << 96 | chunks[2] << 64 | chunks[1] << 32 | chunks[0]
          value /= (10**col[:scale]).to_f
        end
        case sign
        when 1
          row << value
        when 0
          row << value * -1
        end
      end

    when :money
      datalen = data.slice!(0, 1).unpack('C')[0]
      if datalen == 0
        row << nil
      else
        raw = data.slice!(0, datalen)
        rev = raw.slice(4, 4) << raw.slice(0, 4)
        row << rev.unpack('q')[0]/10000.0
      end

    when :smallmoney
      datalen = data.slice!(0, 1).unpack('C')[0]
      if datalen == 0
        row << nil
      else
        row << data.slice!(0, datalen).unpack('l')[0] / 10000.0
      end

    when :smalldatetime
      datalen = data.slice!(0, 1).unpack('C')[0]
      if datalen == 0
        row << nil
      else
        days = data.slice!(0, 2).unpack('S')[0]
        minutes = data.slice!(0, 2).unpack('S')[0] / 1440.0
        row << DateTime.new(1900, 1, 1) + days + minutes
      end

    when :datetime
      datalen = data.slice!(0, 1).unpack('C')[0]
      if datalen == 0
        row << nil
      else
        days = data.slice!(0, 4).unpack('l')[0]
        minutes = data.slice!(0, 4).unpack('l')[0] / 1440.0
        row << DateTime.new(1900, 1, 1) + days + minutes
      end

    when :rawint
      row << data.slice!(0, 4).unpack('V')[0]

    when :bigint
      row << data.slice!(0, 8).unpack("H*")[0]

    when :smallint
      row << data.slice!(0, 2).unpack("v")[0]

    when :smallint3
      row << [data.slice!(0, 3)].pack("Z4").unpack("V")[0]

    when :tinyint
      row << data.slice!(0, 1).unpack("C")[0]

    when :bitn
      has_value = data.slice!(0, 1).unpack("C")[0]
      if has_value == 0
        row << nil
      else
        row << data.slice!(0, 1).unpack("C")[0]
      end

    when :bit
      row << data.slice!(0, 1).unpack("C")[0]

    when :image
      str = ''
      len = data.slice!(0, 1).unpack('C')[0]
      str = data.slice!(0, len) if len && len > 0
      row << str.unpack("H*")[0]

    when :int
      len = data.slice!(0, 1).unpack("C")[0]
      raw = data.slice!(0, len) if len && len > 0

      case len
      when 0, 255
        row << ''
      when 1
        row << raw.unpack("C")[0]
      when 2
        row << raw.unpack('v')[0]
      when 4
        row << raw.unpack('V')[0]
      when 5
        row << raw.unpack('V')[0] # XXX: missing high byte
      when 8
        row << raw.unpack('VV')[0] # XXX: missing high dword
      else
        info[:errors] << "invalid integer size: #{len} #{data[0, 16].unpack("H*")[0]}"
      end
    else
      info[:errors] << "unknown column type: #{col.inspect}"
    end
  end

  info[:rows] << row
  info
end

#mssql_prelogin_packet ⇒ Object 



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# File 'lib/rex/proto/mssql/client_mixin.rb', line 89

def mssql_prelogin_packet
  pkt = ""
  pkt_hdr = ""
  pkt_data_token = ""
  pkt_data = ""


  pkt_hdr = [
      TYPE_PRE_LOGIN_MESSAGE, #type
      STATUS_END_OF_MESSAGE, #status
      0x0000, #length
      0x0000, # SPID
      0x00, # PacketID
      0x00 #Window
  ]

  version = [0x55010008, 0x0000].pack("Vv")

  # if manually set, we will honour
  if tdsencryption == true
    encryption = ENCRYPT_ON
  else
    encryption = ENCRYPT_NOT_SUP
  end

  instoptdata = "MSSQLServer\0"

  threadid = "\0\0" + Rex::Text.rand_text(2)

  idx = 21 # size of pkt_data_token
  pkt_data_token << [
      0x00, # Token 0 type Version
      idx , # VersionOffset
      version.length, # VersionLength

      0x01, # Token 1 type Encryption
      idx = idx + version.length, # EncryptionOffset
      0x01, # EncryptionLength

      0x02, # Token 2 type InstOpt
      idx = idx + 1, # InstOptOffset
      instoptdata.length, # InstOptLength

      0x03, # Token 3 type Threadid
      idx + instoptdata.length, # ThreadIdOffset
      0x04, # ThreadIdLength

      0xFF
  ].pack('CnnCnnCnnCnnC')

  pkt_data << pkt_data_token
  pkt_data << version
  pkt_data << encryption
  pkt_data << instoptdata
  pkt_data << threadid

  pkt_hdr[2] = pkt_data.length + 8

  pkt = pkt_hdr.pack('CCnnCC') + pkt_data
  pkt
end

#mssql_print_reply(info) ⇒ Object 



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# File 'lib/rex/proto/mssql/client_mixin.rb', line 59

def mssql_print_reply(info)
  print_status("SQL Query: #{info[:sql]}")

  if info[:done] && info[:done][:rows].to_i > 0
    print_status("Row Count: #{info[:done][:rows]} (Status: #{info[:done][:status]} Command: #{info[:done][:cmd]})")
  end

  if info[:errors] && !info[:errors].empty?
    info[:errors].each do |err|
      print_error(err)
    end
  end

  if info[:rows] && !info[:rows].empty?

    tbl = Rex::Text::Table.new(
      'Indent'    => 1,
      'Header'    => "Response",
      'Columns'   => info[:colnames],
      'SortIndex' => -1
    )

    info[:rows].each do |row|
      tbl << row.map{ |x| x.nil? ? 'nil' : x }
    end

    print_line(tbl.to_s)
  end
end

#mssql_send_recv(req, timeout = 15, check_status = true) ⇒ Object 



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# File 'lib/rex/proto/mssql/client_mixin.rb', line 171

def mssql_send_recv(req, timeout=15, check_status = true)
  sock.put(req)

  # Read the 8 byte header to get the length and status
  # Read the length to get the data
  # If the status is 0, read another header and more data

  done = false
  resp = ""

  while(not done)
    head = sock.get_once(8, timeout)
    if !(head && head.length == 8)
      return false
    end

    # Is this the last buffer?
    if head[1, 1] == "\x01" || !check_status
      done = true
    end

    # Grab this block's length
    rlen = head[2, 2].unpack('n')[0] - 8

    while(rlen > 0)
      buff = sock.get_once(rlen, timeout)
      return if not buff
      resp << buff
      rlen -= buff.length
    end
  end

  resp
end

#mssql_tds_encrypt(pass) ⇒ Object

Encrypt a password according to the TDS protocol (encode)



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# File 'lib/rex/proto/mssql/client_mixin.rb', line 209

def mssql_tds_encrypt(pass)
  # Convert to unicode, swap 4 bits both ways, xor with 0xa5
  Rex::Text.to_unicode(pass).unpack('C*').map {|c| (((c & 0x0f) << 4) + ((c & 0xf0) >> 4)) ^ 0xa5 }.pack("C*")
end

#mssql_xpcmdshell(cmd, doprint = false, opts = {}) ⇒ Object 



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# File 'lib/rex/proto/mssql/client_mixin.rb', line 214

def mssql_xpcmdshell(cmd, doprint=false, opts={})
  force_enable = false
  begin
    res = query("EXEC master..xp_cmdshell '#{cmd}'", false, opts)
    if res[:errors] && !res[:errors].empty?
      if res[:errors].join =~ /xp_cmdshell/
        if force_enable
          print_error("The xp_cmdshell procedure is not available and could not be enabled")
          raise RuntimeError, "Failed to execute command"
        else
          print_status("The server may have xp_cmdshell disabled, trying to enable it...")
          query(mssql_xpcmdshell_enable())
          raise RuntimeError, "xp_cmdshell disabled"
        end
      end
    end

    mssql_print_reply(res) if doprint

    return res

  rescue RuntimeError => e
    if e.to_s =~ /xp_cmdshell disabled/
      force_enable = true
      retry
    end
    raise e
  end
end

#parse_prelogin_response(resp) ⇒ Object 



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# File 'lib/rex/proto/mssql/client_mixin.rb', line 151

def parse_prelogin_response(resp)
  data = {}
  if resp.length > 5 # minimum size for response specification
    version_index = resp.slice(1, 2).unpack('n')[0]

    major = resp.slice(version_index, 1).unpack('C')[0]
    minor = resp.slice(version_index+1, 1).unpack('C')[0]
    build = resp.slice(version_index+2, 2).unpack('n')[0]

    enc_index = resp.slice(6, 2).unpack('n')[0]
    data[:encryption] = resp.slice(enc_index, 1).unpack('C')[0]
  end

  if major && minor && build
    data[:version] = "#{major}.#{minor}.#{build}"
  end

  return data
end