FoodCoopShop Server-Side Request Forgery vulnerability

FoodCoopShop is open source software for food coops and local shops. Versions starting with 3.2.0 prior to 3.6.1 are vulnerable to server-side request forgery. In the Network module, a manufacturer account can use the `/api/updateProducts.json` endpoint to make the server send a request to an arbitrary host. This means that the server can be used as a proxy into the internal network where the server is. Furthermore, the checks on a valid image are not adequate, leading to a time of check time of use issue. For example, by using a custom server that returns 200 on HEAD requests, then return a valid image on first GET request and then a 302 redirect to final target on second GET request, the server will copy whatever file is at the redirect destination, making this a full SSRF. Version 3.6.1 fixes this vulnerability.