May 1, 2017
DEF CON CTF Quals 2017: insanity insanity insanity insanity insanity insanity insanity insanity insane
DEF CON Quals were this weekend, and as always, they delivered some of the hardest pwning challenges we’ve seen this year. insanity was not even one of them, but we still spent several hours solving it, and had tons of fun. The concept is a classic: The program implements a custom VM with weird operations, and you have to reverse and exploit it…
Jan 6, 2017
33C3CTF: Challenge Code and Demo Exploits
33C3CTF was organised by the CTF Teams Stratum0, CCCAC and KITCTF. This post is just a short collection of some challenges we made for 33C3CTF, and maybe some more links related to 33C3CTF.
Sep 5, 2016
Tokyo Westerns/MMA CTF: Hastur Writeup
hastur was a web/pwnable/forensics, but really actually pwnable challenge in Tokyo Westerns/MMA CTF 2016. It had three stages with three different flags, with a combined point value of 850.
May 31, 2016
HITB CTF 2016: 'Special Delivery' writeup
Just a small writeup for “Special Delivery” (network 300) from HITB CTF 2016.
Apr 28, 2016
CONFidence 2016 Teaser 'spkac' writeup
This is a writeup for the “spkac” challenge from the CONFidence 2016 Teaser CTF. It was a cryptography challenge worth 200 points.
Jan 3, 2016
32C3 CTF: Ranger writeup
ranger was a pwnable worth 400 points during 32C3 CTF 2015. This is just a brief writeup of my solution, mostly to document a few things (in particular seccomp, which I’ve wanted to document for some time now).
Jan 2, 2016
32C3 CTF: Docker writeup
docker was a pwnable worth 250 points during 32C3 CTF 2015. The goal was to escape from a (slightly non-standard) docker container configuration.
Sep 21, 2015
CSAW 2015 - 'memeshop' writeup
‘memeshop’ was a pwnable worth 400 points in the latest CSAW CTF.
Jun 20, 2015
DEFCON 2015 Qualifiers 'babyecho' writeup
This is my writeup for the “babyecho” challenge from the DEFCON 2015 Qualifiers. It was worth 1 Point. (That’s probably the reason for the name babyecho.) Anyway, since this was my first time exploiting a format string vulnerability, I wanted to make a writeup.
Jun 1, 2015
Squareroots & KITCTF at GPN15
This announcement was intentionally left german.
Apr 26, 2015
PlaidCTF 2015 - TP writeup
tp was an exploitation challenge consisting of two parts, in total woth 620 points. For PlaidCTF we (KITCTF) teamed up with StratumAuhuur as “Eat Sleep Pwn Repeat” and me and Stephen worked together to solve this challenge during the CTF.
Mar 30, 2015
Advanced Heap Exploitation: 0CTF 2015 'freenote' writeup
freenote was a pwnable worth 400 points during 0CTF 2015.
Mar 27, 2015
Boston Key Party 2015 'Wood Island' writeup
Originally, I wanted to write up the write-up for the airport challenge, but since Niklas has already done that, I’m doing the Wood Island challenge instead. It was worth 150 points on the Boston Key Party 2015.
Mar 16, 2015
Smashing the Potato: Codegate 2015 'mashed_potato' writeup
mashed_potato was a pwnable worth 600 points during Codegate CTF 2015.
Mar 2, 2015
Boston Key Party 2015 'Sullivan Square' writeup
Sullivan Square was a reversing challenge worth 350 points at the Boston Key Party CTF 2015.
Mar 1, 2015
Boston Key Party 2015 'Airport' writeup
Airport was a cryptography challenge worth 500 points at the Boston Key Party CTF 2015.
Jan 19, 2015
GITS 2015 CTF 'aart' writeup
aart was a web challenge worth 200 points at the 2015 GITS CTF. There were several ways to solve it, three of which will be described here.
Jan 18, 2015
GITS 2015 CTF 'giggles' writeup
giggles was an exploitation challenge worth 300 points at the “Ghost in the Shellcode” CTF 2015.
Jan 12, 2015
InsomniHack Teaser - elysium writeup
Just a quick writeup for the elysium (200pts) challenge from the InsomniHack Teaser CTF 2015. We ended up making the 6th place during the CTF :)
Jan 9, 2015
31C3 CTF 'saas' writeup
saas was an exploitation challenge worth 50 points at the 31C3 CTF.
Dec 30, 2014
31C3 CTF 'mynx' writeup
tl;dr 1 byte overwrite => use after free condition => information leak through a format string. Combined again with the first two steps to gain code execution via a controlled call to system().
Dec 30, 2014
31C3 CTF 'devilish' writeup
devilish was a web challenge worth 30 points at the 31C3 CTF.
Dec 11, 2014
CTFs are about the skill, not about the tools. Still, you’ll need a couple of tools to be successful.
In general a good advice is to get used to working with the OS shell. There’s really a lot of things you can do very quickly and effectively if you know your way around bash/zsh/your_favourite_shell_here and python or your_favourite_scripting_language_here.
Dec 1, 2014
9447 CTF 2014 'europe' writeup
During 9447 CTF 2014, europe was a series of 3 exploitation challenges, all using the same binary. Each one would yield a different flag and in total those three flags where worth 700 points (200, 120, 380).
Nov 13, 2014
Staying up-to-date in infosec
tl;dr just subscribe to r/netsec on reddit.
The following is a list of sources to help you stay up-to-date in infosec. If you’re just starting out it probably still can’t hurt to read some of the posts and try to understand them. More often than not they’ll also point you to introductory resources for the topic.
Nov 13, 2014
Getting Started with CTF
We’ve created a small guide to get you started with CTF and more or less infosec in general. There are a few selected resources for each of the major CTF disciplines that should help you get up to speed in those.
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