Woosun Song

Woosun Song

CS @ GATech

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A list of all the posts and pages found on the site. For you robots out there is an XML version available for digesting as well.

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The Plight of TTY in the Linux Kernel

10 minute read

Published:

Introduction

I solved a bunch of pwnable tasks from zer0pts CTF 2020. Despite the fact that one person wrote most of the challenges in diverse categories (I think that’s really admirable) the quality of tasks was impressive. I hope the organizers get a chance to do it next year too.

Exploiting a type confusion bug in radare2’s pyc plugin

22 minute read

Published:

Introduction

Recently I got the change to author 2 challenges for CodegateCTF 2020 quals. I wrote two pwnable tasks, babyllvm and marshal. The second one, marshal was released 12 hours before the end and therefore didn’t get any solves, despite the fact that it isn’t that difficult. On the other hand babyllvm was released at the start of the CTF and was solved by PPP in just 2 hours, which is very impressive (but expected, it’s PPP…) I’m going to describe how I thought of the idea for this challenge in this post. If you want to go straight to the exploit, go straight to the end.

Balsn CTF 2019 - KrazyNote

37 minute read

Published:

I solved a challenge called KrazyNote on Balsn CTF 2019. As expected, Balsn CTF was extremely hard, and the pwnable challenge with the most solves was KrazyNote. It had about 10 solves, which is quite a lot but I learned a lot of important stuff through this challenge so I decided to publish a write-up for it.

DEFCON CTF 27 Review

11 minute read

Published:

pre CTF (2019.8.7-8)

Our team. KaisHackGoN was qualified to the DEFCON CTF 27 Finals. We arrived about a day early by reserving a room for an extra day at planet hollywood hotel. The first day due to the flight we were all in bad condition. We had our meal at Gordon Ramsay burger and went to sleep early.

Setting up gdb for MIPS pwnables

2 minute read

Published:

This week, I decided to solve a challenge on pwnable.kr called mipstake. It is a simple mips userspace pwnable, but since I did not have any MIPS device I went through some painful processes during the debugging environment setup. In this post, I will be introducing the usage of qemu-system-mips to emulate MIPS userspace binaries and debug them using GDBserver.

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