Room / Challenge: Wave Second For Git (Misc)

Metadata

  • Author: jameskaois
  • CTF: WannaGame Freshman CTF 2025
  • Challenge: Wave Second For Git (Misc)
  • Difficulty: Medium
  • Points: 451
  • Solves: 8
  • Date: 06-10-2025

Goal

We have to get the flag by using Git cli.

My Solution

Here is the source, you can download it here

There is the flag.txt with this content:

VzF7ZzF0aHViXw==

It is encoded with base64 algorithm, it is easy to decode it, result is the first part of the flag:

W1{g1thub_

Now check the source branches with git branch -r:

origin/HEAD -> origin/main
origin/main
origin/second

Let’s move to branch second to see if there is any change git checkout second, the flag.txt changed:

INGESX3JGVPXK4ZTMZ2TO===

It is encoded with base32 algorithm, decode it:

CLI_i5_us3fu7

Now we got 2 parts:

W1{g1thub_CLI_i5_us3fu7

Now check the source with git tag there is part3 tag let’s show it git show part3:

tag part3
Tagger: KetSoSad102 <phanlamdung2006@gmail.com>
Date:   Thu Oct 2 09:24:03 2025 +0700

Zw4bm2:x

I use CyberChef to crack this encoding and found _r1gh7?}

Guide image

Flag is: W1{g1thub_CLI_i5_us3fu7_r1gh7?}