Ruixuan Li (Tsinghua University), Chaoyi Lu (Tsinghua University), Baojun Liu (Tsinghua University;Zhongguancun Laboratory), Yunyi Zhang (Tsinghua University), Geng Hong (Fudan University), Haixin Duan (Tsinghua University;Zhongguancun Laboratory), Yanzhong Lin (Coremail Technology Co. Ltd), Qingfeng Pan (Coremail Technology Co. Ltd), Min Yang (Fudan University), Jun Shao (Zhejiang Gongshang University)

DNS-Based Blocklist (DNSBL) has been a longstanding, effective mitigation against malicious emails. While works have focused on evaluating the quality of such blocklists, much less is known about their adoption, end-to-end operation, and security problems. Powered by industrial datasets of nondelivery reports within 15 months, this paper first performs largescale measurements on the adoption of DNSBLs, reporting their prevalent usage by busy email servers. From an empirical study on the end-to-end operation of 29 DNSBL providers, we find they heavily rely on capture servers, concealed infrastructure to lure blind senders of spam, in generating blocklists. However, we find such capture servers can be exploited and report the HADES attack, where non-abusive email servers are deliberately injected into popular DNSBLs. Legitimate emails from victims will then be broadly rejected by their peers. Through field tests, we demonstrate the attack is effective at low costs: we successfully inject our experimental email servers into 14 DNSBLs, within a time frame ranging from as fast as three minutes to no longer than 24 hours. Practical assessment also uncovers significant attack potential targeting high-profile victims, e.g., large email service providers and popular websites. Upon responsible disclosure, five DNSBL providers have acknowledged the issue, and we also propose possible mitigation. Findings of this paper highlight the need for revisiting DNSBL security and guidelines in its operation.

View More Papers

What’s Done Is Not What’s Claimed: Detecting and Interpreting...

Chang Yue (Institute of Information Engineering, Chinese Academy of Sciences, Beijing, China), Kai Chen (Institute of Information Engineering, Chinese Academy of Sciences, Beijing, China), Zhixiu Guo (Institute of Information Engineering, Chinese Academy of Sciences, Beijing, China), Jun Dai, Xiaoyan Sun (Department of Computer Science, Worcester Polytechnic Institute), Yi Yang (Institute of Information Engineering, Chinese Academy…

Read More

Revisiting EM-based Estimation for Locally Differentially Private Protocols

Yutong Ye (Institute of software, Chinese Academy of Sciences & Zhongguancun Laboratory, Beijing, PR.China.), Tianhao Wang (University of Virginia), Min Zhang (Institute of Software, Chinese Academy of Sciences), Dengguo Feng (Institute of Software, Chinese Academy of Sciences)

Read More

Alba: The Dawn of Scalable Bridges for Blockchains

Giulia Scaffino (TU Wien), Lukas Aumayr (TU Wien), Mahsa Bastankhah (Princeton University), Zeta Avarikioti (TU Wien), Matteo Maffei (TU Wien)

Read More

Revealing the Black Box of Device Search Engine: Scanning...

Mengying Wu (Fudan University), Geng Hong (Fudan University), Jinsong Chen (Fudan University), Qi Liu (Fudan University), Shujun Tang (QI-ANXIN Technology Research Institute; Tsinghua University), Youhao Li (QI-ANXIN Technology Research Institute), Baojun Liu (Tsinghua University), Haixin Duan (Tsinghua University; Quancheng Laboratory), Min Yang (Fudan University)

Read More