Pwning, reversing, and other random security stuff.
This weekend, I played saarCTF 2020 with NoPwnIntended. We got 9th place. This CTF was attack/defense, my favorite style, and I really enjoyed the “SchlossbergCaves” challenge, where you had to pwn a custom compiled programming language. This was also the challenge were we got the most attack points.
It’s been so long since I posted something to this blog! Let’s start again with a nice challenge from this weekend’s Dragon CTF Teaser. This web/pwn challenge is named “rms”. It showcases what can happen when you use non-reentrant library functions in a multithreaded application. A “rms-fixed” version was also released a while later to fix an unintended solution.
I love browser exploitation. Must be something about breaking what I consider to be one of the most complex pieces of software we run every day. At 35C3 CTF this year (I played with KJC + mhackeroni, we got first place!) there was a Chrome challenge about exploiting a bug in V8, Chrome’s JavaScript engine. The bug caused incorrect typing during static analysis, producing incorrect optimizations in…
This week, we spritzers played X-MAS CTF 2018. We enjoyed this week-long event, and took the chance to mix things up a bit (e.g., web guys playing pwn). While I’m mainly a pwner, recently I’ve been getting into crypto. I found “A white rabbit in a snowstorm” to be an interesting challenge. It’s probably trivial for the more experienced crypto guys out there, but I had never broken a (very)…
At last year’s Pwn2Win, we (spritzers) were the only team to solve the SGX challenge. We played again this year, getting 6th place. There was another trusted computing challenge (pwn), on TPM 2.0 this time: we kept up the tradition and were the only team to solve it. So here’s a writeup, enjoy :)
This weekend I played Kaspersky Industrial CTF 2018 with spritzers, where we got 7th place. Not bad considering most of us couldn’t play (and I slept way too much :P). I liked “modcontroller”, a pwn challenge worth 994 points in the end. It actually was more of a web challenge than a pwn one, and I enjoyed doing something different than usual.
Last weekend, I played HITCON CTF 2018 for a bit with our spritzers team. I did not have much free time, so I ended up focusing on a single hard challenge: Secret Note (342 points, pwn/crypto). I have been doing pwn for a while, but recently I have also become interested in crypto, so it looked like fun, and indeed it was!
I’m a big fan of American Fuzzy Lop. It’s a robust and effective coverage-guided fuzzer, and it supports a QEMU mode to fuzz closed-source binaries. QEMU mode, however, comes with a significant performance price. Can we make it better?
From the 2nd to the 5th of August 2018, Italian Hacker Camp was held in Padova, Italy. It was an amazing event - I highly recommend my Italian (and not!) fellows to participate. As spritzers, we played and won the internal CTF. Among the challenges I pwned, I particularly enjoyed “The Lollipop Service” - heap exploitation with a custom allocator.
This weekend I was busy playing RCTF 2018 with the mhackeroni team (we qualified for DEFCON last week - super pumped!). I really liked one of the pwnables, “stringer”. It was a heap challenge where I had to force calloc to not clear a chunk, which I thought was pretty cool.