ALLES! CTF 2020 – Actual ASLR 1/2

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


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Google CTF 2018 (Quals) – writeup JS safe 2.0

The qualifications for the Google Capture The Flag 2018 (ctftime.org) ran from 23/06/2018, 00:00 UTC to 24/06/2018 23:59 UTC.

The CTF was worked out very well. There have been plenty of interesting and creative challenges.

This time I decided to focus on the category web and managed to solve the challenge JS safe 2.0, which was the easiest one of the web-challenges based on the amount of solves. Nevertheless it really took my some time to dodge all the pitfalls I stumbled upon while solving the challenge.

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angstromCTF 2018 – writeup hellcode

The angstromCTF 2018 (ctftime.org) ran from 16/03/2018, 20:00 UTC to 23/03/2018 00:00 UTC.

As the description on ctftime.org states, the ctf is primarily geared towards high school students but with a very wide range of challenge difficulty.

There have been a lot of interesting challenges which have been fun to do. I decided to make a writeup for the pwn challenge hellcode.

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