H1-5411 CTF Writeup

So, Hackerone posted a tweet about the Meme CTF Where barcode was in the tweet image by scanning it and decoding from hex I found this link : https://h1-5411.h1ctf.com/ where we can create/generate a memes and for generating the meme this was used form GitHub which i found in source code analysis …

<?php
  require_once("../includes/config.php");

  if (isset($_FILES['f'])) {
    $new_memes = unserialize(base64_decode(file_get_contents($_FILES['f']['tmp_name'])));
    
    $_SESSION['memes'] = array_merge($_SESSION['memes'], $new_memes);
  }

  header("Location: /memes.php");
?>