Posts

Hi. I’m Vie. I’m an artist. I’m a surfer. I’m a security researcher. I’m a 4-time DEF CON CTF winner with the black badge to prove it. I’m a member of Maple Bacon, and MMM, and now BBB - the organizer of DEF CON CTF 34. You may have heard of me. Over the past 6 years, I’ve started making a name for myself in the CTF community. From becoming the leader of Maple Bacon, to graduating from UBC and working at Google, to doing talks in Switzerland, to travelling the world with Hackceler8, to winning DEF CON CTF 4 times in a row. And finally, the current, most recent milestone: organizing DEF CON CTF as the co-lead of the Benevolent Bureau of Birds. ...

Because the internet runs on JavaScript, and JavaScript is famously known as a language held together with paper clips and rubber bands, the topic of proper sandboxing and safe JS execution became a pretty popular discussion in the security community. I wanted to explore some small and common gotchas that I’ve seen in recent times regarding JS sandboxes, including and based off of a real-world example I saw at work. ...

1 CTF. 2 full days of hacking. 3 teams. 4 victories. When we won last year, our hat-trick, we were the first in DEF CON’S history to do it. 3 consecutive victories, 8x3 (24) black badges awarded in 3 total years. I think it was safe to say that a reputation formed around us and naturally, speculation. PPP and The Duck already had their own reputations so it’s not like the secrets and rumors and awe towards MMM came out of nowhere. However, it’s not like MMM was the only team that did well enough to have a reputation in the CTF community. ...

In 2009, a group students at the Carnegie Mellon University formed a computer security club known as the Plaid Parliament of Pwning, abbreviated to PPP, to participate in Capture the Flag contests. The team saw numerous successes throughout their tenure, and many of the CMU folks with their roots in PPP went on to succeed professionally in cybersecurity-related careers. 2 such members went on to co-create Theori.io, a leading platform of security solutions covering everything from security education to audits and consulting. Their presence exists in both South Korea and USA, and they have their own CTF team, The Duck, that dominates leaderboards whenever they play. ...

DUCTF 2024 has concluded this summer, and I decided to take a look at it with Maple Bacon and solve a few challenges. This is specifically a writeup for “Prisoner-Processor”, the hardest web challenge available. My teammate Angus and I solved this together. It was a great challenge and ventured into alot of interesting things about Bun and TypeScript, so kudos to the authors for making such an interesting challenge! ...

I am aware that the main target audience of my tiny blog are CTF players looking for my writeups and other like-minded security researchers exploring topics I like. But my 2024 resolution was to relive and unite my artistic persona that I spent most of my teen years curating, and marrying that to the security career life I live now. Part of my fine arts training involved a good deal of literature. I wanted to write some random stuff really badly, and this post came out of that desire, I understand it’s out of left field especially given the content of my other work here. If people like this I’d be happy to intersperse more of this into my usual stuff of writeups and security research. ...

MapleCTF’s 2nd annual CTF was held at the same time as Hackceler8 preparation week, so for a brief couple of days in Japan I was busy helping organize 2 ctfs at once, which I don’t recommend. This year, I decided to spice things up with my chals, my vie chals, by incorporating a fun prize for whichever team manages to solve all of my challenges.I had 3 challenges: JaVieScript, Blade Runner, and Jujutsu Kaisen. The first 2 I won’t detail writeups as they’re beginner-friendly and there already exist plenty of writeups for them. The latter one I will detail an author writeup for. ...

Beginning Back in October of 2019, I was attending my 3rd/4th? year at UBC, where I tried to play in a beginner-friendly CTF known as “CSAW 2019” with UBC’s team: Maple Bacon. Particularly, I tried out a challenge called Unagi, which, having spent an eternity on, I managed to solve after hours of wrangling with the problem. To be completely frank, I solved the challenge after googling “XML vulnerability” and trying out payloads - really, just, throwing payloads and modifying them to tailor the challenge - until one stuck and I got the flag. I was happy, but I also thought, “what the hell did I achieve? what did the payload do? What did I learn?” and I couldn’t come up with an answer I was satisfied with. I really just googled information about XML vulenrabilities, found an XXE payload, and threw it hoping to see if something would change (I didn’t even know what XXE stood for). Granted, I still needed to modify the payload. Unagi required more effort than just a copy-paste. But overall, my first experience was largely juvenile and I was still as naive as I was pre CSAW 2019. ...

I was a guest challenge writer for perfect blue’s CTF held mid February. We play-tested each others chals :P MAKIMA Challenge Description Makima simps check in here I’m actually a Power stan. I just needed an excuse for people to look at my Makima drawing. TL;DR Hide php in image, making a PHP/image polyglot X-Accel-Header redirection through CDN to reach internal .php files and access /uploads/your_img.png/lol.php to execute PHP The important parts The default.conf, which is the config used for the nginx proxy server, has an RCE vulnerability: ...

MapleCTF 2022 ran this year to great success, which is fantastic given the tight timeframe we were operating on shortly after coming back from DEFCON 30. We held a beginner-friendly, UBC-local version back in January, so our endgame for this version was to make more creative and harder challenges that people hopefully enjoyed. I wrote 3 web challenges for this CTF: honksay, Viene Library and Art Gallery, the latter 2 I will detail here. I hope you enjoyed them if you played! ...