In the system and network administration domain, gender diversity remains a distant target. The experiences and perspectives of sysadmins who belong to marginalized genders (non cis-men) are not well understood beyond the fact that sysadmin work environments are generally not equitable. We address this knowledge gap in our study by focusing on the ways in which sysadmins from marginalized genders manage their work in men-dominated sysadmin work spaces and by understanding what an inclusive workplace would look like. Using a feminist research approach, we engaged with a group of 16 sysadmins who are not cis-men via six online focus groups. We found that managing the impact of gender identity in the sysadmin workplace means demonstrating excellence and going above and beyond in system administration tasks, and also requires performing additional care work not expected from cis men. Furthermore, our participants handle additional layers of work due to gender considerations and to actively find community in the workplace. We found that sysadmins manage by going above and beyond in their tasks, performing care work and doing extra layers of work because of gender considerations, and finding community in the workplace. To mitigate this additional workload, we recommend more care for care work. For future research, we recommend the use of feminist lenses when studying sysadmin work in order to provide more equitable solutions that ultimately contribute to improving system security by fostering a just workplace. @en

In just a few years, the issue of “digital sovereignty” has emerged as an important security issue for governments across the globe, reflecting a growing unease about the security risks associated with government services that depend on foreign service providers for digital infrastructure and traffic routing. This work investigates to which extent government services and communication with citizens relies on infrastructure outside their own jurisdiction for six countries facing sensitive or sometimes even antagonistic relations with neighbors: India, the Netherlands, Pakistan, Taiwan, Ukraine, and the United Kingdom. By combining various methods (traceroute measurements, passive DNS data and geolocation), we determine where and how domains are hosted, as well as the network paths taken by citizens' traffic to them. We uncover different strategies and degrees of autonomy, as well as difficult tradeoffs between different risks to autonomy, some of which might be larger than the risks associated with the dependency on foreign providers. This includes transnational providers being used by all countries, with geopolitical rivals even being tenants on the same network and traffic between citizens and governments regularly traversing international borders. Furthermore, we compared our empirical findings to stated governmental policies and find that they are not always consistent.

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With the worldwide COVID-19 pandemic in 2020 and 2021 necessitating working from home, corporate Virtual Private Networks (VPNs) have become an important item securing the continued operation of companies around the globe. However, due to their different use case, corporate VPNs and how users interact with them differ from public VPNs, which are now commonly used by end-users. In this paper, we present a first explorative study of eleven experts' and seven non-experts' mental models in the context of corporate VPNs. We find a partial alignment of these models in the high-level technical understanding while diverging in important parameters of how, when, and why VPNs are being used. While, in general, experts have a deeper technical understanding of VPN technology, we also observe that even they sometimes hold false beliefs on security aspects of VPNs. In summary, we show that the mental models of corporate VPNs differ from those for related security technology, e.g., HTTPS. Our findings allow us to draft recommendations for practitioners to encourage a secure use of VPN technology (through training interventions, better communication, and system design changes in terms of device management). Furthermore, we identify avenues for future research, e.g., into experts' knowledge and balancing privacy and security between system operators and users.@en

Security misconfigurations and neglected updates commonly lead to systems being vulnerable. Especially in the context of websites, we often find pages that were forgotten, that is, they were left online after they served their purpose and never updated thereafter. In this paper, we introduce new methodology to detect such forgotten or orphaned web pages. We combine historic data from the Internet Archive with active measurements to identify pages no longer reachable via a path from the index page, yet stay accessible through their specific URL. We show the efficacy of our approach and the real-world relevance of orphaned web-pages by applying it to a sample of 100,000 domains from the Tranco Top 1M. Leveraging our methodology, we find 1,953 pages on 907 unique domains that are orphaned, some of which are 20 years old. Analyzing their security posture, we find that these pages are significantly ((p < 0.01) using (χ2)) more likely to be vulnerable to cross-site scripting (XSS) and SQL injection (SQLi) vulnerabilities than maintained pages. In fact, orphaned pages are almost ten times as likely to suffer from XSS (19.3%) than maintained pages from a random Internet crawl (2.0%), and maintained pages of websites with some orphans are almost three times as vulnerable (5.9%). Concerning SQLi, maintained pages on websites with some orphans are almost as vulnerable (9.5%) as orphans (10.8%), and both are significantly more likely to be vulnerable than other maintained pages (2.7%). Overall, we see a clear hierarchy: Orphaned pages are the most vulnerable, followed by maintained pages on websites with orphans, with fully maintained sites being least vulnerable. We share an open source implementation of our methodology to enable the reproduction and application of our results in practice.

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Asset discovery is fundamental to any organization's cybersecurity efforts. Indeed, one must accurately know which assets belong to an IT infrastructure before the infrastructure can be secured. While practitioners typically rely on a relatively small set of well-known techniques, the academic literature on the subject is voluminous. In particular, the Internet measurement research community has devised a number of asset discovery techniques to support many measurement studies over the past five years. In this paper, we systematize asset discovery techniques by constructing a framework that comprehensively captures how network identifiers and services are found. We extract asset discovery techniques from recent academic literature in security and networking and place them into the systematized framework. We then demonstrate how to apply the framework to several case studies of asset discovery workflows, which could aid research reproducibility. These case studies further suggest opportunities for researchers and practitioners to uncover and identify more assets than might be possible with traditional techniques. @en

"Moving fast, and breaking things", instead of "being safe and secure", is the credo of the IT industry. However, if we look at the wide societal impact of IT security incidents in the past years, it seems like it is no longer sustainable. Just like in the case of Equifax, people simply forget updates, just like in the case of Maersk, companies do not use sufficient network segmentation. Security certification does not seem to help with this issue. After all, Equifax was IS027001 compliant. In this paper, we take a look at how we handle and (do not) learn from security incidents in IT security. We do this by comparing IT security incidents to early and later aviation safety. We find interesting parallels to early aviation safety, and outline the governance levers that could make the world of IT more secure, which were already successful in making flying the most secure way of transportation.

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The DNS TXT resource record is the one with the most flexibility for its contents, as it is a largely unstructured. Although it might be the ideal basis for storing any form of text-based information, it also poses a security threat, as TXT records can also be used for malicious and unintended practices. Yet, TXT records are often overlooked in security research. In this paper, we present the first structured study of the uses of TXT records, with a specific focus on security implications. We are able to classify over 99.54% of all TXT records in our dataset, finding security issues including accidentally published private keys and exploit delivery attempts. We also report on our lessons learned during our large-scale, systematic analysis of TXT records.

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We outline possible approaches to cybersecurity governance and compare them against the proposed European Union network of competence centers. We survey stakeholders for their opinions about the centers and analyze the results.

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Network protocols define how networked computer systems exchange data. As they define all aspects of this communication, the way they are designed is also security sensitive. If communication is supposed to be encrypted, this has to be outlined in the protocol’s specification. If services implementing the protocol should allow for authentication, this has to be defined in the protocol. Hence, the way a protocol is designed is elemental for the security of systems later implementing it. Security by design starts with the protocol definition. Especially in today’s fast-moving environment, with cloud services and the Internet of Things, engineers constantly have to develop new protocols. In this chapter, we derive guidelines for designing new protocols securely, as well as recommendations on how existing protocols can be adjusted to become more secure. We base these recommendations on our analysis of how – historical – protocols were designed and which underlying design decisions made their corresponding implementations susceptible to security issues.@en

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, and (iii) that unintended IPv6 connectivity is a major security issue for unaware system administrators.@en

Nowadays, security incidents have become a familiar “nuisance,” and they regularly lead to the exposure of private and sensitive data. The root causes for such incidents are rarely complex attacks. Instead, the attacks are straight-forward, and they are enabled by simple misconfigurations, such as authentication not being required, or security updates not being installed. For example, the leak of over 140 million Americans’ private data from Equifax’s systems ranks among most severe misconfigurations in recent history: The underlying vulnerability was long known, and a security patch had been readily available for months, but it was never applied. Ultimately, Equifax blamed an employee for forgetting to update the affected system, highlighting the personal responsibility of that operator. In this paper, we investigate the operators’ perspective on security misconfigurations to approach the human component of this class of security issues. We focus our analysis on system operators, as although they are the relevant actors managing the affected systems, they have not yet received significant attention by prior research. We follow an inductive approach and apply a multi-step empirical methodology: (i) a qualitative study to understand how to approach the target group and measure the misconfiguration phenomenon, and (ii) a quantitative survey rooted in the qualitative data. We then provide the first analysis of system operators’ perspective on security misconfigurations, and we determine the factors that operators perceive as the root causes. Based on our findings, we provide practical recommendations on how to reduce security misconfigurations’ frequency and impact. @en

Reverse DNS (rDNS) is regularly used as a data source in Internet measurement research. However, existing work is polarized on its reliability, and new techniques to collect active IPv6 datasets have not yet been sufficiently evaluated. In this paper, we investigate active and passive data collection and practical use aspects of rDNS datasets.We observe that the share of non-authoritatively answerable IPv4 rDNS queries reduced since earlier studies and IPv6 rDNS has less non-authoritatively answerable queries than IPv4 rDNS. Furthermore, we compare passively collected datasets with actively collected ones, and we show that they enable observing the same effects in rDNS data. While highlighting opportunities for future research, we find no immediate challenges to the use of rDNS as active and passive data-source for Internet measurement research. @en

Infrastructure-as-a-Service (IaaS), and more generallythe “cloud,” like Amazon Web Services (AWS) or MicrosoftAzure, have changed the landscape of system operations on theInternet. Their elasticity allows operators to rapidly allocate anduse resources as needed, from virtual machines, to storage, tobandwidth, and even to IP addresses, which is what made thempopular and spurred innovation.In this paper, we show that the dynamic component pairedwith recent developments in trust-based ecosystems (e.g., SSLcertificates) creates so far unknown attack vectors. Specifically, wediscover a substantial number of stale DNS records that point toavailable IP addresses in clouds, yet, are still actively attempted tobe accessed. Often, these records belong to discontinued servicesthat were previously hosted in the cloud. We demonstrate that itis practical, and time and cost efficient for attackers to allocateIP addresses to which stale DNS records point. Consideringthe ubiquity of domain validation in trust ecosystems, like SSLcertificates, an attacker can impersonate the service using avalid certificate trusted by all major operating systems andbrowsers. The attacker can then also exploit residual trust inthe domain name for phishing, receiving and sending emails, orpossibly distribute code to clients that load remote code from thedomain (e.g., loading of native code by mobile apps, or JavaScriptlibraries by websites).Even worse, an aggressive attacker could execute the attackin less than 70 seconds, well below common time-to-live (TTL) forDNS records. In turn, it means an attacker could exploit normalservice migrations in the cloud to obtain a valid SSL certificatefor domains owned and managed by others, and, worse, that shemight not actually be bound by DNS records being (temporarily)stale, but that she can exploit caching instead.We introduce a new authentication method for trust-based domainvalidation that mitigates staleness issues without incurringadditional certificate requester effort by incorporating existingtrust of a name into the validation process. Furthermore, weprovide recommendations for domain name owners and cloudoperators to reduce their and their clients’ exposure to DNSstaleness issues and the resulting domain takeover attacks.@en

Virtual switches are a crucial component of SDN-based cloud systems, enabling the interconnection of virtual machines in a flexible and “software-defined” manner. This paper raises the alarm on the security implications of virtual switches. In particular, we show that virtual switches not only increase the attack surface of the cloud, but virtual switch vulnerabilities can also lead to attacks of much higher impact compared to traditional switches. We present a systematic security analysis and identify four design decisions which introduce vulnerabilities. Our findings motivate us to revisit existing threat models for SDN-based cloud setups, and introduce a new attacker model for SDN-based cloud systems using virtual switches. @en

Virtual switches are a crucial component of cloud operating systems that interconnect virtual machines in a flexible manner. They implement complex network protocol parsing in the unified packet parser - parsing all supported packet header fields in a single pass - and are commonly co-located with the virtualization layer. We find that this significantly reduces the barrier for low-budget attackers to launch high impact attacks in the cloud. This leads us to introduce the virtual switch attacker model for packet-parsing, in short the vAMP attack. Using OpenStack, a cloud operating system, and Open vSwitch, a virtual switch, we demonstrate how current virtual switch designs cannot withstand vAMP. Thereby giving a weak attacker full control of the cloud in a matter of minutes

The vAMP Attack: Taking Control of Cloud Systems via the Unified Packet Parser | Request PDF. Available from: https://www.researchgate.net/publication/320745119_The_vAMP_Attack_Taking_Control_of_Cloud_Systems_via_the_Unified_Packet_Parser [accessed Mar 14 2018].@en

Current large-scale IPv6 studies mostly rely on non-public datasets, asmost public datasets are domain specific. For instance, traceroute-based datasetsare biased toward network equipment. In this paper, we present a new methodologyto collect IPv6 address datasets that does not require access to restrictednetwork vantage points. We collect a new dataset spanning more than 5.8 millionIPv6 addresses by exploiting DNS’ denial of existence semantics (NXDOMAIN).This paper documents our efforts in obtaining new datasets of allocated IPv6 addresses,so others can avoid the obstacles we encountered.@en

Along with the significant growth in the popularity of smartphones and the number of available mobile applications, the amount of threats that harm users or compromise their privacy has dramatically increased. The mobile security research community constantly uncovers new threats and develops associated mitigations. Recently, there is an increasing interest in the human factors and various studies investigated user-aspects in the implementation of security mechanisms as well as users’ perception of threats. In this paper we present a qualitative study on end-users’ knowledge and perceptions of threats and mitigations on mobile devices. Moreover, we identify feelings surrounding smartphone security and privacy. We interpret these feelings in the context of basic psychological need fulfillment. Our findings suggest that so-far little considered aspects of why end-users do not utilize mitigations reside in the need fulfillment plane, and not only in the conflict of usability and security. Following these findings we give examples of how developers of mitigations could ensure that these mitigations are actually adopted by end-users.@en

Nearly every modern mobile device includes two cameras. With advances in technology the resolution of these sensors has constantly increased. While this development provides great convenience for users, for example with video-telephony or as dedicated camera replacement, the security implications of including high resolution cameras on such devices has yet to be considered in greater detail. With this paper we demonstrate that an attacker may abuse the cameras in modern smartphones to extract valuable information from a victim. First, we consider exploiting a front-facing camera to capture a user’s keystrokes. By observing facial reflections, it is possible to capture user input with the camera. Subsequently, individual keystrokes can be extracted from the images acquired with the camera. Furthermore, we demonstrate that these cameras can be used by an attacker to extract and forge the fingerprints of a victim. This enables an attacker to perform a wide range of malicious actions, including authentication bypass on modern biometric systems and falsely implicating a person by planting fingerprints in a crime scene. Finally, we introduce several mitigation strategies for the identified threats.@en