arXiv subjects

Koen van Hove

Publications and source records attributed to Koen van Hove.

3 recordsLinked to original sources

arXiv2026

Domijn: The Security of Domain Registrars and the Risk of a Domain Name Takeover

Domain names are key assets for organisation. They anchor an organisation's online presence and reputation, and serve as linking pin for web services and, e.g., email. Consequently, a malicious takeover of a domain can lead to significant damages. Organisations register domain names through so-called registrars, a type of business that plays a key role in the domain name industry. This implies that registrars play an important part in safeguarding against malicious takeovers of domains. In this paper we empirically study how registrars implement security controls to prevent against such takeovers. We focus on the top 10 most popular registrars for the .nl ccTLD. We present the results of this study in light of a model for the impact of domain takeovers, that analyses the possible consequence of a takeover. We contrast this against the impact of two other well-known threats: ransomware and DDoS attacks. We find that all registrars in our study implement relatively effective security measures, but that they fall short in more advanced security controls, such as the proper implementation of two-factor authentication. We also find that a domain takeover can have significant impact, potentially equalling that of a ransomware attack.

cs.CR↗

arXiv2023

Your Vulnerability Disclosure Is Important To Us: An Analysis of Coordinated Vulnerability Disclosure Responses Using a Real Security Issue

It is a public secret that doing email securely is fraught with challenges. We found a vulnerability present at many email providers, allowing us to spoof email on behalf of many organisations. As email vulnerabilities are ten a penny, instead of focusing on yet another email vulnerability we ask a different question: how do organisations react to the disclosure of such a security issue in the wild? We specifically focus on organisations from the public and critical infrastructure sector who are required to respond to such notifications by law. We find that many organisations are difficult to reach when it concerns security issues, even if they have a security contact point. Additionally, our findings show that having policy in place improves the response and resolution rate, but that even with a policy in place, half of our reports remain unanswered and unsolved after 90~days. Based on these findings we provide recommendations to organisations and bodies such as ENISA to improve future coordinated vulnerability disclosure processes.

cs.NI↗

arXiv2022

Rpkiller: Threat Analysis from an RPKI Relying Party Perspective

The Resource Public Key Infrastructure (RPKI) aims to secure internet routing by creating an infrastructure where resource holders can make attestations about their resources. RPKI Certificate Authorities issue these attestations and publish them at Publication Points. Relying Party software retrieves and processes the RPKI-related data from all publication points, validates the data and makes it available to routers so they can make secure routing decisions. In this work, we create a threat model for Relying Party software, where an attacker controls a Certificate Authority and Publication Point. We implement a prototype testbed to analyse how current Relying Party software implementations react to scenarios originating from that threat model. Our results show that all current Relying Party software was susceptible to at least one of the identified threats. In addition to this, we also identified threats stemming from choices made in the protocol itself. Taken together, these threats potentially allow an attacker to fully disrupt all RPKI Relying Party software on a global scale. We performed a Coordinated Vulnerability Disclosure to the implementers and have made our testbed software available for future studies.

cs.CR↗