Jasmin ransomware web panel path traversal PoC

#EducationalPurposes
https://github.com/codesiddhant/Jasmin-Ransomware
I discovered a pre-auth path traversal vulnerability in the Jasmin Ransomware web panel (CVE-2024-30851), allowing an attacker to deanonymize panel operators and dump decryption keys. Jasmin ransomware was observed in a recent TeamCity (CVE-2024-27198, CVE-2024-27199) exploitation campaign (https://twitter.com/brody_n77/status/1765145148227555826)

Screencast from 2024-04-04 18-51-07.webm

Execution after redirect (CWE-698)

The affected endpoint (Jasmin-Ransomware/Web Panel/download_file.php) fails to die() after sending the Location header. This allows an attacker to bypass authentication requirements. The call to readfile is unsanitized allowing an attacker to read arbitrary files.

<?php
session_start();
if(!isset($_SESSION['username']) ){
	header("Location: login.php");
}
$file=$_GET['file'];
if(!empty($file)){
    // Define headers
    header("Cache-Control: public");
    header("Content-Description: File Transfer");
    header("Content-Disposition: attachment; filename=$file");
    header("Content-Type: text/encoded");
    header("Content-Transfer-Encoding: binary");
    
    // Read the file
   readfile($file);