As last year, there were plenty of diversified challenges, which were worked out very well.
I tried to take at least a look at as much challenges as possible and solved the challenge Quantum Key Distribution, which was relatively easy based on the amounts of solves. Within this article I want to share my writeup on this challenge.
The writeup is divided into the following sections:
As every year hacking-lab.com carried out the annual Hacky Easter event with 27 challenges. As usual the variety of the challenges was awesome. I actually got full score this year 🙂 Many thanks to daubsi, who gave me a nudge once in a while on the last challenges (you can find his writeup here).
This article contains my first writeup on a machine from Hack The Box. If you have not checked out Hack The Box yet, I really suggest you do. Aside from providing classical CTF-style challenges, the plattform hosts plenty of vulnerable machines (boxes), which are supposed to be exploited. The boxes tend to be geared to realistic scenarios and are thus an awesome opportunity to increase your own pen testing skills.
In order to prove the exploitation of a machine, there are two different flag files stored on each machine. The first one to acquire is a file called user.txt, which can be read by a low privileged user. The next step after initially exploiting the machine is to escalate privileges gaining access to an administrative user (root access). With this high privileged user a second file called root.txt can be read. Both files contain a flag (an md5sum), which is supposed to be submitted on the Hack The Box website rewarding you with the corresponding points for this machine.
According to those two steps/files the article is divided into the following sections:
For the sixth time in a row now hacking-lab.com carried out the annual HACKvent. Each day from the 1st of december until the 24th a new challenge is published. I would have loved to spend more time on it, but time is a rare resource especially on the days before christmas 😉 After all I managed to solve 21 of 24 tasks:
The goal of this article is to explain in detail how an off-by-one vulnerability on the heap also known as poison null byte can be exploited. Although this technique does not work with the latest libc, I think it can be used very good in order to demonstrate how exploits based on heap-metadata corruption work (also check out shellphish’s how2heap).
In order to do this I created a vulnerable program, which we will use as an example to create such an exploit. If you like to, you can start by analyzing and exploiting the program on your own (at least check out Environment):
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.