software, offensive security research
HackyEaster was awesome again. From a technical point of view there weren’t too much new things, but the creativity of the provided challenges made it really fun. Including the little teaser challenge there were a total amount of 37 challenges. These challenges were divided into different levels. You could only proceed to the next level, if you have earned enough points in the current level. I really liked that new idea.
Continue reading “Hacky Easter 2021 writeup” |
This year’s HACKvent hosted on competition.hacking-lab.com has been as great as every year. There was a total amount of 28 awesome challenges with varying difficulties. |
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
This article contains my writeup on the machine Rope from Hack The Box. I really enjoyed the box, since it provides a total of three custom binaries, which are supposed to be exploited 🙂
The article is divided into the following parts:
→ User
– Initial Recon
– httpserver
– Leak Memory Address
– Exploit Format String Vulnerability
– Escalating from john to r4j (readlogs)
→ Root
– Local Recon
– contact
– Bruteforce
– Libc Leak
– Final Exploit
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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). |
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Easy |
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01 Twisted 02 Just Watch 03 Sloppy Encryption 04 Disco 2 05 Call for Papers 06 Dots 07 Shell we Argument 08 Modern Art 09 rorriM rorriM |
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Medium |
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10 Stackunderflow 11 Memeory 2.0 12 Decrypt0r 13 Symphony in HEX 14 White Box 15 Seen in Steem 16 Every-Thing 17 New Egg Design 18 Egg Storage |
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Hard |
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19 CoUmpact DiAsc 20 Scrambled Egg 21 The Hunt: Misty Jungle 22 The Hunt: Muddy Quagmire 23 The Maze 24 CAPTEG |
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Hidden |
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25 Hidden Egg #1 26 Hidden Egg #2 27 Hidden Egg #3 |
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The nullcon HackIM 2019 CTF (ctftime.org) ran from 01/02/2019, 16:30 UTC to 03/02/2019 04:30 UTC.
I did the pwn challenge babypwn, which was really fun to do. The following article contains my writeup being divided into the following sections:
→ Challenge description
→ Security mechanisms and disassembly
→ Signedness vulnerabilitiy
→ Format string vulnerabilitiy
→ Final exploit
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):
–> heap.zip
Though it is not required to the exploit the program, the source-code might be helpful:
–> heap.c
The article is divided into the following sections:
–> Environment
–> Vulnerable Program
–> Heap Basics
–> Libc-Leak
–> Control Instruction Pointer
–> One Gadget
–> Final Exploit
Continue reading “Heap Exploitation: Off-By-One / Poison Null Byte”
The Meepwn CTF Quals 2018 (ctftime.org) ran from 13/07/2018, 19:00 UTC to 15/07/2018 19:00 UTC.
There were a lot of interesting-looking challenges. As always, time was the limiting factor 😉 I managed to spend 2 hours on saturday morning solving the pwn challenge babysandbox.
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As every year hacking-lab.com carried out the annual Hacky Easter event with 27 challenges. I could not spend as much time as I would have liked to on solving the challenges, but after all I managed to collect 25 of the 27 eggs and focused on this writeup. |
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Easy |
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01 Prison Break 02 Babylon 03 Pony Coder 04 Memeory 05 Sloppy & Paste (mobile) 06 Cooking for Hackers 07 Jigsaw 08 Disco Egg 09 Dial Trial (mobile) |
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Medium |
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10 Level Two 11 De Egg you must (not solved) 12 Patience (mobile) 13 Sagittarius… 14 Same same… 15 Manila greetings 16 git cloak –hard 17 Space Invaders 18 Egg Factory |
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Hard |
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19 Virtual Hen 20 Artist: No Name Yet (not solved) 21 Hot Dog 22 Block Jane 23 Rapbid Learning 24 ELF |
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Hidden |
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25 Hidden Egg #1 26 Hidden Egg #2 27 Hidden Egg #3 |
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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.
