No Keys to the Kingdom Required: A Comprehensive Investigation of Missing Authentication Vulnerabilities in the Wild

Abstract

Nowadays, applications expose administrative endpoints to the Web that can be used for a plethora of security sensitive actions. Typical use cases range from running small snippets of user-provided code for rapid prototyping, administering databases, and running CI/CD pipelines, to managing job scheduling on whole clusters of computing devices. While accessing these applications over the Web make the lives of their users easier, they can be leveraged by attackers to compromise the underlying infrastructure if not properly configured.
In this paper, we comprehensively investigate inadequate authentication mechanisms in such web endpoints. For this, we looked at 25 popular applications and exposed 18 of them to the Internet because they were either vulnerable in their default configuration or were easy to misconfigure. We identified ongoing attacks against 7 of them, some were even compromised within a few hours from the deployment. In an Internet-wide scan of the IPv4 address space, we examine the prevalence of such vulnerable applications at scale. Thereby, we found 4,221 vulnerable instances, enough to create a small botnet with little technical knowledge. We observed these vulnerable instances and found that even after four weeks, more than half of them were still online and vulnerable. Currently, most of the identified vulnerabilities are seen as features of the software and are often not yet considered by common security scanners or vulnerability databases. However, via our experiments, we found missing authentication vulnerabilities to be common and already actively exploited at scale. They thus represent a prevalent but often disregarded danger.