TSG CTF 2024 Writeup

CTFTime event link: https://ctftime.org/event/2424

Writeup

• Web
  1. Toolong Tea
  2. I Have Been Pwned

Background

• Starts: 14 Dec. 2024, 07:00 UTC
• Ends: 15 Dec. 2024, 07:00 UTC

TSG is the official computer society of The University of Tokyo, and also the name of the CTF team organized by its members.

Categories:

• Pwn
• Web
• Crypto
• Misc
• Reversing

Overview

• Team: Black Bauhinia
• Team Solves: 9/26
• Individual Solves: 2/26
• Score: 1164
• Global Rank: 34/306
• Overall Difficulty To Me: ★★★★★☆☆☆☆☆

What I’ve learned in this CTF

• Web
  1. Toolong Tea - Bypass validation via missing type checking
  2. I Have Been Pwned - Information disclosure via PHP errors and Bcrypt truncation