the cr0wn

The UK’s Top Competitive Cyber Security Team

  1. TokyoWesterns CTF 5th 2019: Happy! (Crypto, 242 pts, 36 solves)

    Author: Vtec234 …


  2. Chaos Communication Camp 2019

    Prejudiced Randomness 1 …


  3. Google CTF 2019 Quals: Sandstone (sandbox, 8 solves)

    At 00:58 local time, two minutes before the end of the qualifiers for Google CTF 2019, drenched in sweat and shaking, I launched my exploit. …


  4. Google CTF 2019 Quals: JIT (pwn)

    We read on the internet that Java is slow so we came up with the solution to speed up some computations! …


  5. DEF CON CTF 2019 Quals: babyheap (pwn, 88 solves)

    This weekend I competed in the DEF CON qualifiers with my CTF team the cr0wn. We also joined forces with #2 ranking UK team EmpireCTF, playing under the name EmpireCr0wn. I solved the babyheap challenge, which had a total of 88 solves and was worth 112 points. …


  6. WPICTF 2019: breakingin (pwn)

    For this challenge we were given SSH credentials and told that there was an SSH server listening on localhost on breakingin.wpictf.xyz, but the firewall was blocking external access to this server. However there was a ‘weird’ service listening on port 31337. …


  7. PlaidCTF 2019: Triggered (web)

    For this challenge we have an utter atrocity against mankind, a webserver written entirely in SQL. …


  8. VincCTF 2018

    This was a very enjoyable cryptography-only CTF. It explored common implementation errors in modern cryptosystems, with a focus on elliptic curve signatures, broken combination ciphers, and cryptocurrencies. …


  9. SECCON 2018: Ghostkingdom (web)

    This is a writeup of the Ghostkingdom web challenge from SECCON 2018 Online CTF. …