FreeScout's Customer AJAX Create Modifies Hidden Existing Customer

FreeScout is a free self-hosted help desk and shared mailbox. Prior to version 1.8.214, the Change Customer modal exposes a “Create a new customer” flow via POST /customers/ajax with action=create. Under limited visibility, the endpoint drops unique-email validation. If the supplied email already belongs to a hidden customer, Customer::create() reuses that hidden customer object and fills empty profile fields from attacker-controlled input. Version 1.8.214 fixes the vulnerability.