Roll, Roll, Roll your Root:A Comprehensive Analysis of the First Ever DNSSEC Root KSK Rollover

The DNS Security Extensions (DNSSEC) add authenticity and integrity to the naming system of the Internet. Resolvers that validate information in the DNS need to know the cryptographic public key used to sign the root zone of the DNS. Eight years after its introduction and one year after the originally scheduled date, this key was replaced by ICANN for the first time in October 2018. ICANN considered this event, called a rollover, "an overwhelming success" and during the rollover they detected "no significant outages". In this paper, we independently follow the process of the rollover starting from the events that led to its postponement in 2017 until the removal of the old key in 2019. We collected data from multiple vantage points in the DNS ecosystem for the entire duration of the rollover process. Using this data, we study key events of the rollover. These events include telemetry signals that led to the rollover being postponed, a near real-time view of the actual rollover in resolvers and a significant increase in queries to the root of the DNS once the old key was revoked. Our analysis contributes significantly to identifying the causes of challenges observed during the rollover. We show that while from an end-user perspective, the roll indeed passed without major problems, there are many opportunities for improvement and important lessons to be learned from events that occurred over the entire duration of the rollover. Based on these lessons, we propose improvements to the process for future rollovers

Addressing the challenges of modern DNS:a comprehensive tutorial

The Domain Name System (DNS) plays a crucial role in connecting services and users on the Internet. Since its first specification, DNS has been extended in numerous documents to keep it fit for today’s challenges and demands. And these challenges are many. Revelations of snooping on DNS traffic led to changes to guarantee confidentiality of DNS queries. Attacks to forge DNS traffic led to changes to shore up the integrity of the DNS. Finally, denial-of-service attack on DNS operations have led to new DNS operations architectures. All of these developments make DNS a highly interesting, but also highly challenging research topic. This tutorial – aimed at graduate students and early-career researchers – provides a overview of the modern DNS, its ongoing development and its open challenges. This tutorial has four major contributions. We first provide a comprehensive overview of the DNS protocol. Then, we explain how DNS is deployed in practice. This lays the foundation for the third contribution: a review of the biggest challenges the modern DNS faces today and how they can be addressed. These challenges are (i) protecting the confidentiality and (ii) guaranteeing the integrity of the information provided in the DNS, (iii) ensuring the availability of the DNS infrastructure, and (iv) detecting and preventing attacks that make use of the DNS. Last, we discuss which challenges remain open, pointing the reader towards new research areas

A security analysis of email communications

The objective of this report is to analyse the security and privacy risks of email communications and identify technical countermeasures capable of mitigating them effectively. In order to do so, the report analyses from a technical point of view the core set of communication protocols and standards that support email communications in order to identify and understand the existing security and privacy vulnerabilities. On the basis of this analysis, the report identifies and analyses technical countermeasures, in the form of newer standards, protocols and tools, aimed at ensuring a better protection of the security and privacy of email communications. The practical implementation of each countermeasure is evaluated in order to understand its limitations and identify potential technical and organisational constrains that could limit its effectiveness in practice. The outcome of the above mentioned analysis is a set of recommendations regarding technical and organisational measures that when combined properly have the potential of more effectively mitigating the privacy and security risks of today's email communications.JRC.G.6-Digital Citizen Securit

Understanding the Security and Performance of the Web Presence of Hospitals: A Measurement Study

Using a total of 4,774 hospitals categorized as government, non-profit, and proprietary hospitals, this study provides the first measurement-based analysis of hospitals' websites and connects the findings with data breaches through a correlation analysis. We study the security attributes of three categories, collectively and in contrast, against domain name, content, and SSL certificate-level features. We find that each type of hospital has a distinctive characteristic of its utilization of domain name registrars, top-level domain distribution, and domain creation distribution, as well as content type and HTTP request features. Security-wise, and consistent with the general population of websites, only 1\% of government hospitals utilized DNSSEC, in contrast to 6\% of the proprietary hospitals. Alarmingly, we found that 25\% of the hospitals used plain HTTP, in contrast to 20\% in the general web population. Alarmingly too, we found that 8\%-84\% of the hospitals, depending on their type, had some malicious contents, which are mostly attributed to the lack of maintenance. We conclude with a correlation analysis against 414 confirmed and manually vetted hospitals' data breaches. Among other interesting findings, our study highlights that the security attributes highlighted in our analysis of hospital websites are forming a very strong indicator of their likelihood of being breached. Our analyses are the first step towards understanding patient online privacy, highlighting the lack of basic security in many hospitals' websites and opening various potential research directions.Comment: 10 pages, 5 tables, 10 figure

A matter of degree:characterizing the amplification power of open DNS resolvers

Open DNS resolvers are widely misused to bring about reflection and amplification DDoS attacks. Indiscriminate efforts to address the issue and take down all resolvers have not fully resolved the problem, and millions of open resolvers still remain available to date, providing attackers with enough options. This brings forward the question if we should not instead focus on eradicating the most problematic resolvers, rather than all open resolvers indiscriminately. Contrary to existing studies, which focus on quantifying the existence of open resolvers, this paper focuses on infrastructure diversity and aims at characterizing open resolvers in terms of their ability to bring about varying attack strengths. Such a characterization brings nuances to the problem of open resolvers and their role in amplification attacks, as it allows for more problematic resolvers to be identified. Our findings show that the population of open resolvers lies above 2.6M range over our one-year measurement period. On the positive side, we observe that the majority of identified open resolvers cut out when dealing with bulky and DNSSEC-related queries, thereby limiting their potential as amplifiers. We show, for example, that 59% of open resolvers lack DNSSEC support. On the downside, we see that a non-negligible number of open resolvers facilitate large responses to ANY and TXT queries (8.1% and 3.4% on average, respectively), which stands to benefit attackers. Finally we show that by removing around 20% of potent resolvers the global DNS amplification potential can be reduced by up to 80%

LIGHTest: Lightweight Infrastrucutre for Global and Heterogeneous Trust Management

The EU-funded LIGHTest project is developing a global trust infrastructure that enables an easy and efficient verification process of electronic transactions, even if the involved instances belong to different trust domains. LIGHTest builds on the available internet Domain Name System (DNS) infrastructure. This paper gives an overview on the LIGHTest project, its reference architecture and variety of application fields

Risky Business: Social Trust and Community in the Practice of Cybersecurity for Internet Infrastructure

The security of computer networks and systems on the Internet is a growing and ongoing set of concerns for nation states, corporations, and individuals. Although substantial and valuable work is in progress to secure the hardware and software technologies of the Internet, less attention has been paid to the everyday practices of the people involved in maintaining this infrastructure. In this paper, we focus on issues in cybersecurity as they apply to computer networks, to show how effective practices of network security are premised upon social relationships of trust formed within communities of cybersecurity professionals, and enacted in the practice of cybersecurity. We describe three key cybersecurity problems that involve Internet infrastructural technologies: IP address hijacking, email spam, and DNS spoofing. Through our analysis of these three problems, we argue that social trust between people – not just assurances built into the underlying technologies – must be emphasized as a central aspect of securing Internet infrastructure

Simulated penetration testing and mitigation analysis

Da Unternehmensnetzwerke und Internetdienste stetig komplexer werden, wird es immer schwieriger, installierte Programme, Schwachstellen und Sicherheitsprotokolle zu überblicken. Die Idee hinter simuliertem Penetrationstesten ist es, Informationen über ein Netzwerk in ein formales Modell zu transferiern und darin einen Angreifer zu simulieren. Diesem Modell fügen wir einen Verteidiger hinzu, der mittels eigener Aktionen versucht, die Fähigkeiten des Angreifers zu minimieren. Dieses zwei-Spieler Handlungsplanungsproblem nennen wir Stackelberg planning. Ziel ist es, Administratoren, Penetrationstestern und der Führungsebene dabei zu helfen, die Schwachstellen großer Netzwerke zu identifizieren und kosteneffiziente Gegenmaßnahmen vorzuschlagen. Wir schaffen in dieser Dissertation erstens die formalen und algorithmischen Grundlagen von Stackelberg planning. Indem wir dabei auf klassischen Planungsproblemen aufbauen, können wir von gut erforschten Heuristiken und anderen Techniken zur Analysebeschleunigung, z.B. symbolischer Suche, profitieren. Zweitens entwerfen wir einen Formalismus für Privilegien-Eskalation und demonstrieren die Anwendbarkeit unserer Simulation auf lokale Computernetzwerke. Drittens wenden wir unsere Simulation auf internetweite Szenarien an und untersuchen die Robustheit sowohl der E-Mail-Infrastruktur als auch von Webseiten. Viertens ermöglichen wir mittels webbasierter Benutzeroberflächen den leichten Zugang zu unseren Tools und Analyseergebnissen.As corporate networks and Internet services are becoming increasingly more complex, it is hard to keep an overview over all deployed software, their potential vulnerabilities, and all existing security protocols. Simulated penetration testing was proposed to extend regular penetration testing by transferring gathered information about a network into a formal model and simulate an attacker in this model. Having a formal model of a network enables us to add a defender trying to mitigate the capabilities of the attacker with their own actions. We name this two-player planning task Stackelberg planning. The goal behind this is to help administrators, penetration testing consultants, and the management level at finding weak spots of large computer infrastructure and suggesting cost-effective mitigations to lower the security risk. In this thesis, we first lay the formal and algorithmic foundations for Stackelberg planning tasks. By building it in a classical planning framework, we can benefit from well-studied heuristics, pruning techniques, and other approaches to speed up the search, for example symbolic search. Second, we design a theory for privilege escalation and demonstrate the applicability of our framework to local computer networks. Third, we apply our framework to Internet-wide scenarios by investigating the robustness of both the email infrastructure and the web. Fourth, we make our findings and our toolchain easily accessible via web-based user interfaces