An unprotected user enumeration vulnerability exists in the account email update endpoint, allowing authenticated users to verify whether email addresses are registered on the panel through automated requests without rate limiting or CAPTCHA protection.
Details
The account settings page allows authenticated users to update their email address through a POST request. Unlike the login and password reset forms which implement reCAPTCHA and rate limiting protections, this endpoint lacks these safeguards entirely.
An attacker can capture the email update request (for example, using Burp Suite's proxy) and modify the email field to test arbitrary addresses. The panel's response will confirm whether each tested email is already registered in the system. Because there are no rate limits implemented, attackers can send hundreds or thousands of requests to enumerate the user base.
This is concerning because:
The login and password reset pages correctly implement protections against enumeration
The account page has no reCAPTCHA option available
No rate limiting exists in the panel for this endpoint
Authentication is required, but any valid account (including free tier/trial accounts) can exploit this
PoC
Log into the Pterodactyl panel with any valid account
Navigate to Account Settings
Open Burp Suite (or similar proxy tool) and configure your browser to proxy through it
Attempt to change your email address and capture the POST request