Use of cryptographically weak PRNG in the password recovery token generation of Revive Adserver < v4.2.1 causes a potential authentication bypass attack if an attacker exploits the password recovery functionality. In lib/OA/Dal/PasswordRecovery.php, the function generateRecoveryId() generates a password reset token that relies on the PHP uniqid function and consequently depends only on the current server time, which is often visible in an HTTP Date header.