Katsushi-kawamori Magic Login Mail or QR Code vulnerabilities

The Magic Login Mail or QR Code plugin for WordPress is vulnerable to Privilege Escalation in all versions up to, and including, 2.05. This is due to the plugin storing the magic login QR code image with a predictable, static filename (QR_Code.png) in the publicly accessible WordPress uploads directory during the email sending process. The file is only deleted after wp_mail() completes, creating an exploitable race condition window. This makes it possible for unauthenticated attackers to trigger a login link request for any user, including administrators, and then exploit the race condition between QR code file creation and deletion to obtain the login URL encoded in the QR code, thereby gaining unauthorized access to the targeted user's account.