Serverless computing has revolutionized cloud computing by offering users an efficient, cost-effective way to develop and deploy applications without managing infrastructure details. However, serverless cloud users remain vulnerable to various types of attacks, including micro-architectural side-channel attacks. These attacks typically rely on the physical co-location of victim and attacker instances, and attackers need to exploit cloud schedulers to achieve co-location with victims. Therefore, it is crucial to study vulnerabilities in serverless cloud schedulers and assess the security of different serverless scheduling algorithms. This study addresses the gap in understanding and constructing co-location attacks in serverless clouds. We present a comprehensive methodology to uncover exploitable features in serverless scheduling algorithms and to devise strategies for constructing co-location attacks via normal user interfaces. In our experiments, we successfully reveal exploitable vulnerabilities and achieve instance co-location on prevalent open-source infrastructures and Microsoft Azure Functions. We also present a mitigation strategy, the Double-Dip scheduler, to defend against co-location attacks in serverless clouds. Our work highlights critical areas for security enhancements in current cloud schedulers, offering insights to fortify serverless computing environments against potential co-location attacks.

翻译：无服务器计算通过为用户提供一种无需管理基础设施细节即可高效、经济地开发和部署应用程序的方式，彻底改变了云计算。然而，无服务器云用户仍然容易受到各类攻击，包括微架构侧信道攻击。这类攻击通常依赖于受害者实例与攻击者实例的物理共置，攻击者需要利用云调度器来实现与受害者的共置。因此，研究无服务器云调度器中的漏洞并评估不同无服务器调度算法的安全性至关重要。本研究旨在填补对无服务器云中共置攻击的理解与构建方面的空白。我们提出了一套全面的方法论，用于揭示无服务器调度算法中可利用的特性，并设计通过正常用户界面构建共置攻击的策略。在我们的实验中，我们成功地揭示了可利用的漏洞，并在主流的开源基础设施及Microsoft Azure Functions上实现了实例共置。我们还提出了一种防御策略，即Double-Dip调度器，以抵御无服务器云中的共置攻击。我们的工作突显了当前云调度器中需要加强安全性的关键领域，为强化无服务器计算环境以防范潜在的共置攻击提供了见解。