Author:
BitFriends

Language:
C/C++

Upload:
12:45 PM 06/06/2020

Platform
Unix/linux etc.

Difficulty:
2.5

Quality:
4.0

Arch:
x86-64

Description

Welcome to this crackme. Only executing shellcode on the stack, which executes /bin/sh is a valid solution. Do not make the stack executeable with a tool. Do not patch. I hope that you will learn how to bypass nx. Aslr has to be disabled with "echo 0 /proc/sys/kernel/randomize_va_space". If you are stuck, a little hint will be in the comments. Good luck!

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BitFriends on 11:30 AM 06/07/2020: Hint: Ever heard of signals?

dovetail on 7:50 PM 03/16/2021: Are you intending on a signal related system call to be used here? The only thing I can think of is using mprotect to remove the nx bits from the stack. I'm not sure how signals can be used to bypass nx but I'd like to learn. I've definitely been stuck on this one a while haha.

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