CTF Writeups

R3izorr/CTF_writeup

A growing collection of reverse engineering and binary exploitation writeups across ImaginaryCTF, Midnight Flag, K17, BITS, Osu, tkb and others.

Markdown Python pwntools Ghidra gdb #ctf #pwn #rev #notes
Python updated Apr 2026 active

CTF_writeup is my long-form CTF notebook. It collects challenge notes, exploit scripts, and breakdowns from events I play — with a strong bias toward reverse engineering and binary exploitation.

A curated subset is re-published as MDX inside this site’s Writeups section. The full working directory — including challenge binaries, libc/ld, Docker setups, and solve scripts — lives in the source repository on GitHub.

What lives there

  • Heap bugs on modern glibc (2.34 / 2.39) with safe-linking bypasses, tcache poisoning, and exit-handler forgery.
  • Classic reverse-engineering challenges: small VMs, obfuscated Go, Nim binaries, Android/NDK targets, custom ciphers.
  • A few web / full-stack chains where the real bug is in a native component reached through a web front.
  • Occasional crypto and OSINT notes when the category shows up.

How I take notes

Each writeup starts with a short triage: protections, libc, a rough plan. Then I walk the exploit in readable pieces — leaks, primitives, the pivot, and the trigger — with the finished solve.py at the end.

The goal is for the write-up to teach the approach, not only the payload.