01 Oct 2024

rev, pwn, hardware

TISC'24 Writeups #3

This is the final part of my TISC write-ups, detailing my solutions to level 10-12. Level 10: Diffuse (Misc) Level 11: Sandboxed Notes App (Pwn) Level 12: Revenge of the Dragon (Pwn) Diffuse This is a puzzle-type challenge. Each individual step is easy; the difficulty lies in finding every clue...


01 Oct 2024

web3, web, rev

TISC'24 Writeups #2

This is a continuation of my TISC writeups. This post will cover stage 6-9. Level 6: Noncevigator (Web3) Level 7: Baby Flagchecker (Web3/Rev) Level 8: Wallfacer (Rev) Level 9: Imphash (Pwn) Noncevigator We are given a Solidity smart contract Noncevigator.sol, with the challenge description: 1 2 3 It seems like...


01 Oct 2024

web, rev, forensics

TISC'24 Writeups #1

Over the past week or so, I have been playing TISC, CSIT’s annual CTF. I managed to solve all 12 challenges in 11 days, coming in 1st. TISC is an individual CTF hosted by CSIT that is open to all Singaporeans. The challenges roughly get progressively more difficult. You must...


16 Apr 2024

pwn, blockchain, vm

baby-bear-blockchain Writeup

This was a pwn challenge from the recent Amateurs CTF that I first-blooded. The challenge utilised an internal VM from a Solana validator client, Firedancer, and involved finding vulnerabilities in the VM implementation. Interestingly, Firedancer is a clone of the Rust Solana rbpf library but re-written in C! To temper...


02 Oct 2023

pwn, web, cloud, rev, forensics, crypto

TISC'23 Writeups

Palindrome, everyone’s favourite cybercrime syndicate, is back for TISC 2023. I managed to solve all 10 challenges this year and clinch 2nd place. Here are my write-ups for all 10 levels. Level 1: Disk Archaeology Level 2: XIPHEREHPIX’s Reckless Mistake Level 3: KPA Level 4: Really Unfair Battleships Game Level...


03 Sep 2023

pwn

DUCTF'23 Writeups

Over the weekend, I played DownUnderCTF with my team, Social Enginner Experts, placing 6th overall.


12 Jun 2023

pwn

SEETF'23 Author Writeups

This weekend, Social Engineering Experts (SEE) held its inaugural SEETF. Here are my write-ups for the challenges I authored. I am aware of the (multiple) unintended solutions, but thought it would be good to document my intended solutions. Thanks to everyone who played!


21 May 2023

pwn, rev

GreyCTF pwn write-ups

Over the weekend, I played GreyCTF with Social Engineering Experts, placing 1st locally and 8th internationally. Having not touched CTFs for ages due to NS, I was a bit rusty, but luckily the challenges were nice twists on simple concepts, offering a pleasant mix of difficulty. I focused on the...


05 Mar 2023

pwn, rev, cve

ImageMagick CVE-2020-10251: Exploitation

This is part 2 in the series on the ImageMagick vulnerability CVE-2020-10251. Part 1 discusses how to trigger the vulnerability and touches on how to recover the OOB heap data. This part will look at crafting suitable exploit files and exfiltrating useful information from the heap, making use of a...


05 Mar 2023

pwn, rev, cve

ImageMagick CVE-2020-10251: Vulnerability analysis

In the past, I had done some research in the automated detection of vulnerabilities in binaries. There were a few vulnerabilities that I used as a benchmark for my algorithm to detect, one of which was CVE-2020-25674. This CVE was a bug in ImageMagick, “a widely deployed, general purpose image...


21 Jan 2023

humour, BVT

On funny things

I believe that humour is an important part of many relationships, and sadly, its importance is often overlooked. Many great friendships are built on humour, and humour can also help break the ice between new acquaintances. You need look no further than schoolchildren to see the importance of humour in...


23 Oct 2022

pwn, rev

JadeCTF pwn & rev write-ups

I participated in JadeCTF over the weekend. Having put CTFs on hold for some time for school, these challenges were a nice refresher for me. For these write-ups, I won’t be diving too deep into the details. Instead, I’ll mainly be focusing on the high-level method used to solve the...


31 Aug 2022

pwn, web, cloud, rev, forensics, crypto

CSIT TISC 2022 Write-ups

TISC (The InfoSecurity Challenge) 2022, organised by CSIT, was a CTF held over 17 days. Eager to escape my exam prep, I spent the first few days trying the challenges :) I solved the first 6 challenges in the first week before deciding to resume my studying… The challenges are...


25 Jun 2022

pwn

CDDC Write-ups (ring 3 pwn)

I felt that these ring’s challenges were quite fun, requiring some creative thinking to solve. There was one last challenge in this category which my team didn’t manage to solve (blackbox FSB pwn). You can find the relevant binaries in this repo.


25 Jun 2022

pwn

CDDC Write-ups (ring 4 pwn)

These 3 challenges had a wide variation in difficulty, but were all worth 100 points each (static scoring). You can find the relevant binaries in this repo.


25 Jun 2022

pwn

CDDC Write-ups (ring 5 pwn)

In the recent Cyber Defenders Discovery Camp (CDDC) organised by DSTA, my team “Avocado_Milk” came in 4th with an overall score of 6180 - maybe one day I’ll get that podium finish :). Here are the write-ups for the challenges I solved during the CTF. I’ll be releasing my rev...