Taeyang Lee (@5unkn0wn) / X

Taeyang Lee

432 posts

Taeyang Lee

@5unkn0wn

Taeyang Lee, a security researcher at @theori_io.

Seoul, Republic of Korea

Joined February 2017

Taeyang Lee
@5unkn0wn
Apr 30
Everyone focuses on memory corruption bugs in the Linux kernel, but we shouldn’t overlook logical bugs.
Brian Pak
@brian_pak
Apr 29
Time to talk about this one. CopyFail (CVE-2026-31431) — a 732-byte Python script that roots every Linux distro shipped since 2017. 🧵
Taeyang Lee
@5unkn0wn
Jan 24
This is my first Linux kernel exploit for Google kCTF, and the patch commit is now public: git.kernel.org/pub/scm/linux/… Actually, this bug was found by AI while analyzing 1-day variants, I'd like to share my approach for these AI things to find bug, and exploitation write-up later.
Taeyang Lee
@5unkn0wn
Jan 18, 2025
Recently, @BackEngineerLab released the crackme obfuscated by the CodeDefender and I reversed the binary: gist.github.com/5unKn0wn/24fa0…. The crackme implemented modified SipHash24, and the goal is to find the input that matches the hash. The obfuscation was nice and quite a challenge !
cdcrackme.py
From gist.github.com
Taeyang Lee
@5unkn0wn
Dec 30, 2024
missed firstbloods 🥲
AlpacaHack
@AlpacaHack
Dec 30, 2024
Round 8 (Rev) just ended 🦙 Thank you to all the players who participated! Congratulations to the top 5 players: 1. @5unkn0wn 2. @blin000 3. eba13005b88dce03165e 4. @willington1337 5. @Yu_212_MC
Taeyang Lee
@5unkn0wn
Aug 12, 2024
Fav chall: Helium implements ephemeral key exchange through slightly modified libhydrogen. The most painful but fun part was analyzing whole inlined sse3 functions and identifying modified algorithms. After exchanging the key, we can read the flag via arbitrary file read vuln😋
Theori
@theori_io
Aug 12, 2024
🏆 Theori Wins DEF CON 32 CTF and DARPA AI Cyber Challenge (AIxCC) Semifinals! 🏆 We are thrilled to announce that Theori has once again emerged victorious at DEF CON 32 CTF—the world-renowned "Hacker Olympics"! With this win, Theori secures its 8th overall victory and an

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