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Daily AlpacaHack

A CTF challenge series with fun puzzles to enjoy every day

What is Daily AlpacaHack?

We regularly publish simple, beginner-friendly or educational CTF challenges!

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Solve each challenge within its time window to appear on the leaderboard.

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Today's Challenge
admin
Baby Alpaca
Misc
Welcome🌱
49 solves
Submissions (latest 3)
quaran

SOLVED!

Oct 1, 8:40 AM

ctes091x

SOLVED!

Oct 1, 8:36 AM

Leaderboard

Try the first challenge

Is this your first CTF? Let's begin by tackling the first challenge released on Daily AlpacaHack.

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admin
AlpacaHack 2100
Misc
Welcome🌱
2,235 solves
Upcoming challenges reveal the , , and in advance.
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k0080k0080
what is my pointer 2
Pwn
Hard
37 solves
1
admin
Baby Alpaca
Misc
Welcome🌱
49 solves
2
tan90909090tan90909090
Planned topic.NET
Rev
Easy🌱
3
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Want a harder challenge?

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Writeups

Writeup for what is my pointer 2

lumma

ja
what is my pointer 2

10 hours ago

nirvana

Writeup for what is my pointer 2

michikusamichiya

[AlpacaHack] Flag is A + B

michikusamichiya

[AlpacaHack] typhoon-python writeup

gattoartz

Writeup for base 16-32-64

ja

2026/09/26 23:00

Rows:

Log Viewer

Topic: Remote Code ExecutionReleased: Dec 22, 2025

267 solves
Web
Medium5.0

by

tchen

tchen

Simple log viewer with regex feature.

Beginner Hint: What is an instance spawner?
  • In CTFs, some challenges require dynamically creating a separate challenge server for each player (or team).
  • For example, if a player can change the state of a challenge server, it may affect other players.
  • To handle such issues, an instance spawner is provided.
  • On AlpacaHack, clicking the "Spawn Challenge Server" button automatically creates an isolated challenge server for each user.
  • This challenge also uses an instance spawner.
  • To help reduce server load, please try to solve the challenge locally before spawning.
  • Note that on Daily AlpacaHack, even for challenges that do not require an instance spawner, the challenge server may be stopped after some time has passed since release, and the "Spawn Challenge Server" button will then appear.
Beginner Hint: The Starting Point of the Attack
  • The goal of this challenge is to read the flag file located in the root directory.
  • The starting point for achieving this is an OS command injection in the query part of the awk command.
Beginner Hint: Pitfalls in Payload Construction
  • In Python, subprocess.run method executes commands without going through a shell like Bash.
  • As a result, you cannot split commands using ; or perform command substitution with $(command).
log-viewer.tar.gz

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