Balsn CTF 2021

We are here again! This year, Balsn CTF 2021 will feature creative and interesting challenges. We cordially invite you to join our party. Don't forget to mark it on your calendar!

• Date: 20 Nov. 2021, 10:00 (UTC+8) ~ 22 Nov. 2021, 10:00 (UTC+8)
• Format: 48-hour Online Jeopardy
• CTFTime: event/1376
• Official URL: https://balsnctf.com/
• Prize (updated):
  • 1st place: $40,000 TWD
  • 2nd place: $30,000 TWD
  • 3rd place: $20,000 TWD
  • Balsn CTF 2021 Taiwan Stars (top 3 domestic teams):
    • 1st place: $20,000 TWD
    • 2nd place: $15,000 TWD
    • 3rd place: $10,000 TWD
  • All the prize will be transferred in ETH.
• All of the above information is subject to change.

In Balsn CTF 2021, we will be featuring a new "homework" category, which consists of unsolved challenges from the previous year. See our twitter post for more details.

Congratulations to the following teams:

• Global top 3:

  • 1st place: Water Paddler
  • 2nd place: 10sec
  • 3rd place: Goburin’

• Balsn CTF 2021 Taiwan Stars (domestic top 3):

  • 1st place: 10sec
  • 2nd place: Goburin’
  • 3rd place: BambooFox

• Challenges

  • Web
    • Proxy
    • 4pple Music
    • 0linephp
    • 2linephp
  • Pwn
    • Futex
    • or⊕w
    • NoteEdit
    • Kawaii Note
  • Rev
    • Cheater
    • The g VM 1
    • The g VM 2
    • ML
  • Crypto
    • 1337 pins
    • trinity
    • dlog
  • Misc
    • metaeasy
    • dark knight
    • unicorn’s aisle prelude
  • Sandbox
    • unicorn’s aisle interlude
    • unicorn’s aisle postlude
    • elf fortress
  • Smart Contract
    • Draupnir

Challenges

Web

Proxy

• Solved: 18
• Author: ysc
• Link: https://gist.github.com/YSc21/f8ff767e5142e1ada639a36293b8ec6f

4pple Music

• Solved: 2
• Author: Kaibro
• Link: https://github.com/w181496/My-CTF-Challenges/tree/master/Balsn-CTF-2021#4pple-music

0linephp

• Solved: 6
• Author: Ginoah
• Link: https://gist.github.com/ginoah/6765c60bdf9e7c6cd682ed400094bd2a

2linephp

• Solved: 8
• Author: Kaibro
• Link: https://github.com/w181496/My-CTF-Challenges/tree/master/Balsn-CTF-2021#2linephp

Pwn

Futex

• Solved: 0
• Author: Billy
• Link: https://gist.github.com/st424204/e6395bdbed43b1bf308a4de2ba9d6ba0

or⊕w

• Solved: 15
• Author: how2hack
• Link: https://github.com/how2hack/my-ctf-challenges/tree/master/2021/balsnctf-2021/orxw

NoteEdit

• Solved: 0
• Author: how2hack
• Link: https://github.com/how2hack/my-ctf-challenges/tree/master/2021/balsnctf-2021/NoteEdit

Kawaii Note

• Solved: 1
• Author: kevin47 + Jwang
• Link:

Rev

Cheater

• Solved: 6
• Author: Terrynini
• Link:

The g++ VM 1

• Solved: 7
• Author: Frank Lin
• Link: https://github.com/eee4017/my-ctf-challenges/tree/main/BalsnCTF2021/the_g%2B%2B_virtual_machine_1

The g++ VM 2

• Solved: 6
• Author: Frank Lin
• Link: https://github.com/eee4017/my-ctf-challenges/tree/main/BalsnCTF2021/the_g%2B%2B_virtual_machine_2

ML

• Solved: 22
• Author: sces60107
• Link:

Crypto

1337 pins

• Solved: 5
• Author: sasdf + kevin47
• Link: https://sasdf.github.io/ctf/tasks/2021/BalsnCTF/crypto/1337pins/

trinity

• Solved: 0
• Author: sasdf
• Link: https://sasdf.github.io/ctf/tasks/2021/BalsnCTF/crypto/trinity/

dlog

• Solved: 2
• Author: sasdf
• Link: https://sasdf.github.io/ctf/tasks/2021/BalsnCTF/crypto/dlog/

Misc

metaeasy

• Solved: 22
• Author: nawmrofed
• Link:

dark knight

• Solved: 12
• Author: 424275
• Link:

unicorn’s aisle prelude

• Solved: 12
• Author: Jwang
• Link: https://github.com/jwang-a/CTF/tree/master/MyChallenges/Pwn/Unicorns_Aisle

Sandbox

unicorn’s aisle interlude

• Solved: 1
• Author: Jwang
• Link: https://github.com/jwang-a/CTF/tree/master/MyChallenges/Pwn/Unicorns_Aisle

unicorn’s aisle postlude

• Solved: 0
• Author: Jwang
• Link: https://github.com/jwang-a/CTF/tree/master/MyChallenges/Pwn/Unicorns_Aisle

elf fortress

• Solved: 0
• Author: Jwang
• Link: https://github.com/jwang-a/CTF/tree/master/MyChallenges/Pwn/ElfFortress

Smart Contract

Draupnir

• Solved: 0
• Author: Jwang
• Link: https://github.com/jwang-a/CTF/tree/master/MyChallenges/SmartContract/Draupnir