D-Link DAP-1860 devices before v1.04b03 Beta allow access to administrator functions without authentication via the HNAP_AUTH header timestamp value. In HTTP requests, part of the HNAP_AUTH header is the timestamp used to determine the time when the user sent the request. If this value is equal to the value stored in the device's /var/hnap/timestamp file, the request will pass the HNAP_AUTH check function.
https://supportannouncement.us.dlink.com/announcement/publication.aspx?name=SAP10135
https://chung96vn.wordpress.com/2019/11/15/d-link-dap-1860-vulnerabilities/