Wolf in Sheep's Clothing: Evaluating Security Risks of the Undelegated Record on DNS Hosting Services
Fenglu Zhang, Yunyi Zhang, Baojun Liu, Eihal Alowaisheq, Lingyun Ying, Xiang Li, Zaifeng Zhang, Ying Liu, Haixin Duan, Min Zhang · 2023
Leveraging DNS for covert communications is appealing since most networks allow DNS traffic, especially the ones directed toward renowned DNS hosting services. Unfortunately, most DNS hosting services overlook domain ownership verification, enabling miscreants to host undelegated DNS records of a domain they do not own. Consequently, miscreants can conduct covert communication through such undelegated records for whitelisted domains on reputable hosting providers. In this paper, we shed light on the emerging threat posed by undelegated records and demonstrate their exploitation in the wild. To the best of our knowledge, this security risk has not been studied before.