The ALLES! CTF (ctftime.org) took place from 04/09/2020, 16:00 UTC to 06/09/2020, 19:00 UTC with a variety of interesting, creative challenges.
Within this article I want to share my writeup on the two challenges Actual ASLR 1 and 2, which were authored by LiveOverflow. What I especially liked about the challenge(s) is that you could make progression step by step even getting a first flag on the way to a full shell, which grants access to the second flag.
The article is divided into the following sections:
→Actual ASLR 1
– Binary
– Random Algorithm
– Reimplementation In Python
– First Flag
→Actual ASLR 2
– Custom Heap
– Vulnerability
– Heap Leak
– Image Base Leak
– Overwriting Function Pointer
– Final Exploit
Continue reading “ALLES! CTF 2020 – Actual ASLR 1/2”