Grav v1.7.49.5 / Admin v1.10.49.1 – User Enumeration & Email Disclosure

Summary

A user enumeration and email disclosure vulnerability exists in Grav v1.7.49.5 with Admin plugin v1.10.49.1.
The "Forgot Password" functionality at /admin/forgot leaks information about valid usernames and their associated email addresses through distinct server responses.
This allows an attacker to enumerate users and disclose sensitive email addresses, which can be leveraged for targeted attacks such as password spraying, phishing, or social engineering.

Details

The issue resides in the taskForgot() function, which handles the forgot password workflow.
Relevant vulnerable logic:

if (null === $user || $user->state !== 'enabled' || !$to) {
    ...
    // Generic message for invalid/non-existing users
    $this->setMessage($this->translate('PLUGIN_ADMIN.FORGOT_INSTRUCTIONS_SENT_VIA_EMAIL'));
    return $this->createRedirectResponse($current);
}

if ($rateLimiter->isRateLimited($username)) {
    ...
    $interval = $config->get('plugins.login.max_pw_resets_interval', 2);

    // Sensitive message for valid users
    $this->setMessage($this->translate('PLUGIN_LOGIN.FORGOT_CANNOT_RESET_IT_IS_BLOCKED', $to, $interval), 'error');

    return $this->createRedirectResponse($current);
}

When an attacker submits the password reset form at /admin/forgot with an invalid username, the application responds with:

Instructions to reset your password have been sent to your email address

However, when a valid username is supplied, and the attacker repeatedly triggers password reset requests, the application responds with:

Cannot reset password for <USER_EMAIL>, password reset functionality temporarily blocked, please try later (maximum 60 minutes)

This discrepancy in responses enables:

1. User Enumeration – Attackers can determine if a username exists in the system by analyzing the response.
2. User Email Disclosure – The system discloses the actual email address associated with the account (e.g., [email protected]).

This violates best practices for authentication flows, where responses should remain generic to avoid leaking sensitive information.