Internet-wide scanning is a critical tool for security researchers and practitioners alike. By exhaustively exploring
the entire IPv4 address space, Internet scanning has driven the
development of new security protocols, found and tracked vulnerabilities, improved DDoS defenses, and illuminated global
censorship. Unfortunately, the vast scale of the IPv6 address
space—340 trillion trillion trillion addresses—precludes exhaustive scanning, necessitating entirely new IPv6-specific
scanning methods. As IPv6 adoption continues to grow, developing IPv6 scanning methods is vital for maintaining our
capability to comprehensively investigate Internet security.
We present 6SENSE, an end-to-end Internet-wide IPv6
scanning system. 6SENSE utilizes reinforcement learning coupled with an online scanner to iteratively reduce the space of
possible IPv6 addresses into a tractable scannable subspace,
thus discovering new IPv6 Internet hosts. 6SENSE is driven
by a set of metrics we identify and define as key for evaluating the generality, diversity, and correctness of IPv6 scanning.
We evaluate 6SENSE and prior generative IPv6 discovery
methods across these metrics, showing that 6SENSE is able
to identify tens of millions of IPv6 hosts, which compared
to prior approaches, is up to 3.6x more hosts and 4x more
end-site assignments, across a more diverse set of networks.
From our analysis, we identify limitations in prior generative
approaches that preclude their use for Internet-scale security
scans. We also conduct the first Internet-wide scanning-driven
security analysis of IPv6 hosts, focusing on TLS certificates
unique to IPv6, surveying open ports and security-sensitive
services, and identifying potential CVEs.
more »
« less
Enumerating Active IPv6 Hosts for Large-Scale Security Scans via DNSSEC-Signed Reverse Zones
Security research has made extensive use of exhaustive Internet-wide scans over the recent years, as they can provide significant insights into the overall state of security of the Internet, and ZMap made scanning the entire IPv4 address space practical. However, the IPv4 address space is exhausted, and a switch to IPv6, the only accepted long-term solution, is inevitable. In turn, to better understand the security of devices connected to the Internet, including in particular Internet of Things devices, it is imperative to include IPv6 addresses in security evaluations and scans. Unfortunately, it is practically infeasible to iterate through the entire IPv6 address space, as it is 2^96 times larger than the IPv4 address space. Therefore, enumeration of active hosts prior to scanning is necessary. Without it, we will be unable to investigate the overall security of Internet-connected devices in the future. In this paper, we introduce a novel technique to enumerate an active part of the IPv6 address space by walking DNSSEC-signed IPv6 reverse zones. Subsequently, by scanning the enumerated addresses, we uncover significant security problems: the exposure of sensitive data, and incorrectly controlled access to hosts, such as access to routing infrastructure via administrative interfaces, all of which were accessible via IPv6. Furthermore, from our analysis of the differences between accessing dual-stack hosts via IPv6 and IPv4, we hypothesize that the root cause is that machines automatically and by default take on globally routable IPv6 addresses. This is a practice that the affected system administrators appear unaware of, as the respective services are almost always properly protected from unauthorized access via IPv4. Our findings indicate (i) that enumerating active IPv6 hosts is practical without a preferential network position contrary to common belief, (ii) that the security of active IPv6 hosts is currently still lagging behind the security state of IPv4 hosts...
more »
« less
- Award ID(s):
- 1704253
- PAR ID:
- 10097409
- Date Published:
- Journal Name:
- 2018 IEEE Symposium on Security and Privacy
- Page Range / eLocation ID:
- 770 to 784
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
More Like this
-
-
To mitigate IPv4 exhaustion, IPv6 provides expanded address space, and NAT allows a single public IPv4 address to suffice for many devices assigned private IPv4 address space. Even though NAT has greatly extended the shelf-life of IPv4, some networks need more private IPv4 space than what is officially allocated by IANA due to their size and/or network management practices. Some of these networks resort to using squat space , a term the network operations community uses for large public IPv4 address blocks allocated to organizations but historically never announced to the Internet. While squatting of IP addresses is an open secret, it introduces ethical, legal, and technical problems. In this work we examine billions of traceroutes to identify thousands of organizations squatting. We examine how they are using it and what happened when the US Department of Defense suddenly started announcing what had traditionally been squat space. In addition to shining light on a dirty secret of operational practices, our paper shows that squatting distorts common Internet measurement methodologies, which we argue have to be re-examined to account for squat space.more » « less
-
IP addresses are commonly used to identify hosts or properties of hosts. The address assigned to a host may change, however, and the extent to which these changes occur in time as well as in the address space is currently unknown, especially in IPv6. In this work, we take a first step towards understanding the dynamics of IPv6 address assignments in various networks around the world and how they relate to IPv4 dynamics. We present fine-grained observations of dynamics using data collected from over 3,000 RIPE Atlas probes in dual-stack networks. RIPE Atlas probes in these networks report both their IPv4 and their IPv6 address, allowing us to track changes over time and in the address space. To corroborate and extend our findings, we also use a dataset containing 32.7 billion IPv4 and IPv6 address associations observed by a major CDN. Our investigation of temporal dynamics with these datasets shows that IPv6 assignments have longer durations than IPv4 assignments---often remaining stable for months---thereby allowing the possibility of long-term fingerprinting of IPv6 subscribers. Our analysis of spatial dynamics reveals IPv6 address-assignment patterns that shed light on the size of the address pools network operators use in domestic networks, and provides preliminary results on the size of the prefixes delegated to home networks. Our observations can benefit many applications, including host reputation systems, active probing methods, and mechanisms for privacy preservation.more » « less
-
The Domain Name System (DNS) is an essential service for the Internet which maps host names to IP addresses. The DNS Root Sever System operates the top of this namespace. RIPE Atlas observes DNS from more than 11k vantage points (VPs) around the world, reporting the reliability of the DNS Root Server System in DNSmon. DNSmon shows that loss rates for queries to the DNS Root are nearly 10\% for IPv6, much higher than the approximately 2\% loss seen for IPv4. Although IPv6 is ``new,'' as an operational protocol available to a third of Internet users, it ought to be just as reliable as IPv4. We examine this difference at a finer granularity by investigating loss at individual VPs. We confirm that specific VPs are the source of this difference and identify two root causes: VP \emph{islands} with routing problems at the edge which leave them unable to access IPv6 outside their LAN, and VP \emph{peninsulas} which indicate routing problems in the core of the network. These problems account for most of the loss and nearly all of the difference between IPv4 and IPv6 query loss rates. Islands account for most of the loss (half of IPv4 failures and 5/6ths of IPv6 failures), and we suggest these measurement devices should be filtered out to get a more accurate picture of loss rates. Peninsulas account for the main differences between root identifiers, suggesting routing disagreements root operators need to address. We believe that filtering out both of these known problems provides a better measure of underlying network anomalies and loss and will result in more actionable alerts.more » « less
-
more » « less
Summary With the increasing number of Internet of Things (IoT) devices, current networking world is suffering in terms of management and operations with lack of IPv4 addresses leading to issues like network address translation (NAT) proliferation, security and quality of services. Software‐defined networking (SDN) and Internet Protocol version 6 (IPv6) are the new networking paradigms evolved to address related issues of legacy IPv4 networking. To adapt with global competitive environment and avoid all existing issues in legacy networking system, network service providers have to migrate their networks into IPv6 and SDN‐enabled networks. But immediate transformations of existing network are not viable due to several factors like higher cost of migration, lack of technical human resources, lack of standards and protocols during transitions, and many more. In this paper, we present the migration analysis for proper decision making of network transition in terms of customer demand, traffic engineering, and organizational strength with operation expenditure for network migration using evolutionary gaming approach. Joint migration to SDN‐enabled IPv6 network from game theoretic perspective is modeled and is validated using numerical results obtained from simulations. Our empirical analysis shows the evolutionary process of network migration while different internal and external factors in the organization affect the overall migration. Evolutionary game in migration planning is supportive in decision making for service providers to develop suitable strategy for their network migration. The proposed approach for migration decision making is mostly applicable to fairly sustained service providers who lack economics, regulation/policy, and resources strengths.
- Free Publicly Accessible Full Text
-
Accepted Manuscript1.0
- Conference Paper:
- https://doi.org/10.1109/SP.2018.00027
