摘要
Numerous measurement researches have been performed to discover the IPv4 network security issues by leveraging the fast Internet-wide scanning techniques. However, IPv6 brings the 128-bits address space and renders brute-force network scanning impractical. Although significant efforts have been dedicated to enumerating active IPv6 hosts, limited by technique efficiency and probing accuracy, large-scale empirical measurement studies under the increasing IPv6 networks are infeasible now.
To fill this research gap, by leveraging the extensively adopted IPv6 address allocation strategy, we propose a novel IPv6 network periphery discovery approach. Specifically, XMap, a fast network scanner, is developed to find the periphery, such as a home router. We evaluate it on twelve prominent Internet service providers and harvest 52M active peripheries. Grounded on these found devices, we explore IPv6 network risks of the unintended exposed security services and the flawed traffic routing strategies. First, we demonstrate the unintended exposed security services in IPv6 networks, such as DNS, and HTTP, have become emerging security risks by analyzing 4.7M peripheries. Second, by inspecting the periphery’s packet routing strategies, we present the flawed implementations of IPv6 routing protocol affecting 5.8M router devices. Attackers can exploit this common vulnerability to conduct effective routing loop attacks, inducing DoS to the ISP’s and home routers with an amplification factor of >200. We responsibly disclose those issues to all involved vendors and ASes and discuss mitigation solutions. Our research results indicate that the security community should revisit IPv6 network strategies immediately.
在2021年第51届IEEE/IFIP国际可靠系统和网络会议上（线上举办），我分享了论文：Fast IPv6 Network Periphery Discovery and Security Implications。
李想
清华大学博士研究生（网络空间安全）
李想，清华大学网络科学与网络空间研究院四年级博士研究生，导师为李琦副教授和段海新教授。他是网络与系信息安全实验室（NISL）的成员之一，也是奇安信公司的安全研究实习生。目前他作为访问学者在加州大学尔湾分校李洲助理教授研究组进行学术交流。此外，他也是一款开源网络扫描器XMap的开发者与维护者。研究领域涉及网络安全、协议安全、IPv6安全、DNS安全、互联网测量以及网络协议fuzzing。作为第一作者，他目前在网络安全顶级会议发表论文3篇，涵盖USENIX Security、NDSS、DSN。作为合作作者，他也在网络顶级会议发表多篇论文，如USENIX Security和SIGMETRICS。此外，他在工业界顶级安全会议也进行过演讲，如Black Hat。他经常参加相关会议讨论分享最近的研究进展，如IDS、OARC、VehicleSec。在漏洞挖掘领域，他目前已发现多个IPv6和DNS方向的新型重大漏洞并获得140+安全漏洞编号（CVE/CNVD），其中所发现的IPv6漏洞影响了数十家路由器厂商。他也发现了DNS协议设计和实现层面的漏洞，影响了所有DNS的软件和实现。目前他已经获得了多家知名互联网厂商的致谢和奖励（超过$10.6k），包括谷歌、微软、Cloudflare、Akamai等公司，并在积极推进DNS等协议标准的改进（相关工作已被纳入RFC文档）。