Hack The Box – Response

Ever since I played Hack The Box, I have wanted to create a box myself. As the time went by, I encountered so much cool vulnerabilities and techniques both in real-world engagements and CTFs, which I thought would be fun to put in a box. The result of this is Response.

Introduction
User (→ bob)
    – Enumeration
    – Server Side Request Forgery
    – Internal Chat Application
    – Cross-Protocol Request Forgery
Scanning Script (bob → scryh)
    – Make own HTTPS Server being scanned
    – Setting up own DNS Server
    – Setting up own SMTP Server
    – Directory Traversal
Incident Report (scryh → root)
    – Decrypting Meterpreter Session
    – Restoring RSA private key

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ASIS CTF Quals 2021 – ASCII art a a service

The ASIS CTF Quals 2021 (ctftime.org) took place from 22/10/2021, 15:00 UTC to 24/10/2021, 15:00 UTC providing a total amount of 24 challenges.

One of those challenges I really enjoyed was ASCII art as a service. This article contains my writeup for the challenge and is divided into the following sections:

Challenge Description
Source Code
Solution

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Hacky Easter 2021 writeup

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.

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HACKvent20 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.
HV20.(-1) Twelve steps of christmas
HV20.01 Happy HACKvent 2020
HV20.02 Chinese Animals
HV20.03 Packed gifts
HV20.04 Br❤celet
HV20.05 Image DNA
HV20.13 Twelve steps of christmas
HV20.14 Santa’s Special GIFt
HV20.15 Man Commands, Server Lost
HV20.16 Naughty Rudolph
HV20.17 Santa’s Gift Factory Control
HV20.18 Santa’s lost home
HV20.19 Docker Linter Service
HV20.06 Twelve steps of christmas
HV20.07 Bad morals
HV20.08 The game
HV20.09 Santa’s Gingerbread Factory
HV20.10 Be patient with the adjacent
HV20.11 Chris’mas carol
HV20.12 Wiener waltz
HV20.20 Twelve steps of Christmas
HV20.21 Threatened Cat
HV20.22 Padawanlock
HV20.23 Those who make backups are cowards!
HV20.24 Santa’s Secure Data Storage
HV20.H1 It’s a secret!
HV20.H2 Oh, another secret!
HV20.H3 Hidden in Plain Sight
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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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HACKvent19 writeup

This year’s HACKvent was hosted on the brand new Hacking-Lab 2.0 plattform. Each day from the 1st of december until the 24th a new challenge is published raising in difficulty. The flag format changed from HV18-xxxx-xxxx-xxxx-xxxx-xxxx to HV19{...}. After all I managed to solve all 28 challenges 🙂
Hidden
HV19.H1 Hidden One
HV19.H2 Hidden Two
HV19.H3 Hidden Three
HV19.H4 Hidden Four
Easy
HV19.01 censored
HV19.02 Triangulation
HV19.03 Hodor, Hodor, Hodor
HV19.04 password policy circumvention
HV19.05 Santa Parcel Tracking
HV19.06 bacon and eggs
HV19.07 Santa Rider
Medium
HV19.08 SmileNcryptor 4.0
HV19.09 Santas Quick Response 3.0
HV19.10 Guess what
HV19.11 Frolicsome Santa Jokes API
HV19.12 back to basic
HV19.13 TrieMe
HV19.14 Achtung das Flag
Hard
HV19.15 Santa’s Workshop
HV19.16 B0rked Calculator
HV19.17 Unicode Portal
HV19.18 Dance with me
HV19.19 U+1F385
HV19.20 i want to play a game
HV19.21 Happy Christmas 256
Leet
HV19.22 The command … is lost
HV19.23 Internet Data Archive
HV19.24 ham radio

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Google CTF 2019 (Quals) – Quantum Key Distribution

This years online qualification for the Google Capture The Flag finals (ctftime.org) ran from 22/06/2019, 00:01 UTC to 23/06/2019 23:59 UTC.

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:

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Hacky Easter 2019 writeup

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).
Easy
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
Medium
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
Hard
19 CoUmpact DiAsc
20 Scrambled Egg
21 The Hunt: Misty Jungle
22 The Hunt: Muddy Quagmire
23 The Maze
24 CAPTEG
Hidden
25 Hidden Egg #1
26 Hidden Egg #2
27 Hidden Egg #3
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VolgaCTF 2019 Qualifier – Blind

The VolgaCTF 2019 Qualifier (ctftime.org) took place from 29/03/2019, 15:00 UTC to 31/03/2019 15:00 UTC.

There has been a really interesting RSA crypto challenge called Blind, which I would like to share with you in this writeup.

The article is divided into the following sections:

Challenge description
What does the script do?
Blind RSA Signature
Retrieving the Flag

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nullcon HackIM 2019 – babypwn

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

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