Checkmk Werk 12564: Fix possible stored XSS issue when uploading backup keys

ID: 12564 Title: Fix possible stored XSS issue when uploading backup keys Component: Setup Level: 1 Class: Security fix Version: 2.1.0i1 Uploading backup keys could trigger a XSS issue which could lead to execution of arbitrary javascript code in the context of the user currently accessing the setup GUI.