The UPnP endpoint URL /gena.cgi in the D-Link DIR-859 Wi-Fi router 1.05 and 1.06B01 Beta01 allows an Unauthenticated remote attacker to execute system commands as root, by sending a specially crafted HTTP SUBSCRIBE request to the UPnP service when connecting to the local network.
https://www.ftc.gov/system/files/documents/cases/dlink_proposed_order_and_judgment_7-2-19.pdf
https://www.dlink.com/en/security-bulletin
https://supportannouncement.us.dlink.com/announcement/publication.aspx?name=SAP10147
https://supportannouncement.us.dlink.com/announcement/publication.aspx?name=SAP10146
https://medium.com/%40s1kr10s/d-link-dir-859-rce-unautenticated-cve-2019-17621-es-fad716629ff9
https://medium.com/%40s1kr10s/d-link-dir-859-rce-unautenticated-cve-2019-17621-en-d94b47a15104