Host Header Injection

pimcore/admin-ui-classic-bundle is vulnerable to Host Header Injection. The vulnerability is caused due to unsafely using the host header from incoming HTTP requests when generating URLs in the function invitationLinkAction within UserController.php , specifically in the way $loginUrl trusts user input. An attacker can manipulate the HTTP host header in requests to the /admin/user/invitationlink endpoint, resulting in the generation of URLs with the attacker’s domain resulting in further attacks like phishing due to manipulated host header.