Home on Vladimir Albu

teleporter - ROCSC 2026 Finals

Fri, 08 May 2026 00:48:00 +0300

Exploitable Minecraft server plugin that allows players to teleport to each other

Introduction

Teleporter is a CTF task that I created for the final phase of the Romanian Cyber Security Challenge 2026 (ROCSC). It involved exploiting bugs in a teleportation feature provided by a Minecraft Java Edition server plugin.

Task description

We Need to Go Deeper

Version: Java 1.21.11

Author: Albu Vladimir
Category: Misc
Difficulty: Medium

Attachment

Overview

We are given a JAR file containing what seems to be a Minecraft PaperMC server plugin, as well as a server instance to connect to, version being Java 1.21.11.

SimpleNote Writeup - BlitzCTF 2025

Tue, 08 Jul 2025 14:00:25 +0300

UAF-vulnerable note taking app that uses calloc and modern glibc

Task description

Just simple note …

Author: kuvee
Category: Pwn

Attachment

Overview

This is a pwn challenge which has a note system, often met at heap challenges. We are given the option to create, edit, show and delete chunks. There is also a secret function which allows us to get a leak. All protections are enabled and the binary uses a modern libc version. The creation of chunks is done via calloc, which doesn’t look in the tcache directly and also fills the allocated chunk with zeroes. We are also limited to 7 entries in our pointer list, which suggests that we can only have 7 chunks allocated.

Brave Traveler Official Writeup - TFC CTF 2024

Sun, 04 Aug 2024 14:00:00 +0300

Simple reverse engineering task I made that uses BFS algorithm to generate output (OLD)

Task description

There’s a whole world left to explore.

Don’t forget the flag format: TFCCTF{stringOfText}

Author: header
Category: Reverse Engineering

Attachment

Writeup

Explanation of the code

The program starts by making a vector with type set of size 128.

vector<set<char>> v(128);

It calls the function generateMap() with a pointer to the vector v as argument.

generateMap(v);

In the function, we have many modifications to the vector v. The first two are:

About

Mon, 01 Jan 0001 00:00:00 +0000

My name is Vladimir Albu. I am a high school student, cybersecurity enthusiast and CTF player.
I am the captain of a Romanian CTF team called “OctalO” (CTFtime)
Currently learning more web application penetration testing and binary exploitation.

Certifications and associated skills

Burp Suite Certified Practitioner (BSCP) - View certification
- Burp Suite
- Web Application Security

Awards and achievements

This includes competitions and extracurricular activities

2026

🥈 Silver medalist at the International Cybersecurity Olympiad (ICO), 11th place world-wide
🇷🇴 Member of Team Romania at the European Cybersecurity Challenge (ECSC)
🍊 Participated in the ROCSC Bootcamp (ECSC qualifiers)
🥇 1st place at the Romanian National Cyber Security Olympiad (overall)
✍️ Challenge author at ROCSC 2026 Finals
🥇 1st place at the Romanian Regional Cyber Security Olympiad (overall)

2025

🥇 2nd place internationally, best romanian team - DefCamp CTF 2025 Finals (Team OctalO) (fun fact: because the organizers forgot to unfreeze the leaderboard, they thought we won 1st place internationally and awarded us on-stage, only to find out later that TRX actually won)
🇷🇴 Member of Team Romania at ECSC (backup player)
🚩 Qualified for the DefCamp CTF finals by obtaining 4th place out of 491 teams at TFC CTF 2025 (Team OctalO)
📜 BSCP certified
🌲 Participated in the ROCSC Bootcamp (ECSC qualifiers)
🥈 2nd place at the Romanian National Cyber Security Olympiad (10th grade)
🥇 1st place at UNbreakable Romania Team Finals (high school), 2nd overall, (Team “hex on the beach”)
🚩 4th place (high school) at UNbreakable Romania Individual (9th overall)
🥇 1st place at the Romanian Regional Cyber Security Olympiad (10th grade), 2nd overall
🚩 Qualified for ROCSC Finals (6th on junior category, 10th overall)

2024

✍️ Challenge author at TFC CTF 2024, organized by Romania’s best CTF team
🌲 Participated in the ROCSC Bootcamp (ECSC qualifiers)
🥇 1st place at the Romanian National Cyber Security Olympiad (9th grade)
🥇 1st place at the Romanian Regional Cyber Security Olympiad (9th grade), 5th overall