A Capture the Flag (CTF) is a competition where participants hunt for flags (pieces of text such as flag{some_unique_text_or_hopefully_meaningful_message}) hidden inside vulnerable executables, applications, files, and whatnot. These competitions are usually held in the jeopardy format, where each challenge is contained in a separate box and has a number of points attached.
It is a hacking competition, not in the sense of destroying things or developing lousy business ideas, but in breaking things apart to understand how they work and discovering new ways of doing things.
Sharing is Caring: Arbitrary Code Execution for Breakfast
Binary exploitation in C++, gadget mania, and a new form of deserialization attack.
Dynamic Views Loading – Abusing Server Side Rendering in Drogon
What could go wrong releasing a C++ web server with "live reload" into the wild?
From Compression to Compromise: Unmasking Zip File Threats
Deep dive into zip file attacks and mitigations (with examples!).
HKCERT CTF 2023 – Decompetition: Vitamin C++
A beginner-friendly writeup to reverse-engineering C++ a lá decompetition. Years of complex shenanigans condensed!
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N[Subtype Metaprogramming] is N[Mostly Harmless]
Inheritance go brrrrrrrr... abusing turing-complete typesystems to write fun programs in Python.
HITCON 2023 – The Blade
Beginner-friendly writeup for a nifty Rust reversing challenge.
GDB/GEF Cheatsheet
Quick command reference on one of the most powerful tools for dynamic analysis.
DUCTF 2023 – Wrong Signal
You straight to oops(). Right away.
The HKUST Firebird CTF Team
Experiences and reflections journeying with the HKUST Firebird CTF Team.
Remorse
Hiding messages with counterpoint.
HKCERT CTF 2022 – C++harming Website
A harming website? Hope it doesn't harm my sleep!
HKCERT CTF 2022 – Base64 Encryption
Frequency analysis with a touch of heuristics.
DownUnderCTF 2022 – ezpz-rev
Grid puzzles aren't that easy.
TAMUctf 2022 – CTF Sim
Oops, your vpointer was redirected.
TAMUctf 2022 – Labyrinth
Using CFGs to solve a control-flow maze.