Insider threat : memory confidentiality and integrity in the cloud

PhD ThesisThe advantages of always available services, such as remote device backup or data storage, have helped the widespread adoption of cloud computing. However, cloud computing services challenge the traditional boundary between trusted inside and untrusted outside. A consumer’s data and applications are no longer in premises, fundamentally changing the scope of an insider threat. This thesis looks at the security risks associated with an insider threat. Specifically, we look into the critical challenge of assuring data confidentiality and integrity for the execution of arbitrary software in a consumer’s virtual machine. The problem arises from having multiple virtual machines sharing hardware resources in the same physical host, while an administrator is granted elevated privileges over such host. We used an empirical approach to collect evidence of the existence of this security problem and implemented a prototype of a novel prevention mechanism for such a problem. Finally, we propose a trustworthy cloud architecture which uses the security properties our prevention mechanism guarantees as a building block. To collect the evidence required to demonstrate how an insider threat can become a security problem to a cloud computing infrastructure, we performed a set of attacks targeting the three most commonly used virtualization software solutions. These attacks attempt to compromise data confidentiality and integrity of cloud consumers’ data. The prototype to evaluate our novel prevention mechanism was implemented in the Xen hypervisor and tested against known attacks. The prototype we implemented focuses on applying restrictions to the permissive memory access model currently in use in the most relevant virtualization software solutions. We envision the use of a mandatory memory access control model in the virtualization software. This model enforces the principle of least privilege to memory access, which means cloud administrators are assigned with only enough privileges to successfully perform their administrative tasks. Although the changes we suggest to the virtualization layer make it more restrictive, our solution is versatile enough to port all the functionality available in current virtualization viii solutions. Therefore, our trustworthy cloud architecture guarantees data confidentiality and integrity and achieves a more transparent trustworthy cloud ecosystem while preserving functionality. Our results show that a malicious insider can compromise security sensitive data in the three most important commercial virtualization software solutions. These virtualization solutions are publicly available and the number of cloud servers using these solutions accounts for the majority of the virtualization market. The prevention mechanism prototype we designed and implemented guarantees data confidentiality and integrity against such attacks and reduces the trusted computing base of the virtualization layer. These results indicate how current virtualization solutions need to reconsider their view on insider threats

Assessing database and network threats in traditional and cloud computing

Cloud Computing is currently one of the most widely-spoken terms in IT. While it offers a range of technological and financial benefits, its wide acceptance by organizations is not yet wide spread. Security concerns are a main reason for this and this paper studies the data and network threats posed in both traditional and cloud paradigms in an effort to assert in which areas cloud computing addresses security issues and where it does introduce new ones. This evaluation is based on Microsoft’s STRIDE threat model and discusses the stakeholders, the impact and recommendations for tackling each threat

Trusted Computing and Secure Virtualization in Cloud Computing

Large-scale deployment and use of cloud computing in industry is accompanied and in the same time hampered by concerns regarding protection of data handled by cloud computing providers. One of the consequences of moving data processing and storage off company premises is that organizations have less control over their infrastructure. As a result, cloud service (CS) clients must trust that the CS provider is able to protect their data and infrastructure from both external and internal attacks. Currently however, such trust can only rely on organizational processes declared by the CS provider and can not be remotely verified and validated by an external party. Enabling the CS client to verify the integrity of the host where the virtual machine instance will run, as well as to ensure that the virtual machine image has not been tampered with, are some steps towards building trust in the CS provider. Having the tools to perform such verifications prior to the launch of the VM instance allows the CS clients to decide in runtime whether certain data should be stored- or calculations should be made on the VM instance offered by the CS provider. This thesis combines three components -- trusted computing, virtualization technology and cloud computing platforms -- to address issues of trust and security in public cloud computing environments. Of the three components, virtualization technology has had the longest evolution and is a cornerstone for the realization of cloud computing. Trusted computing is a recent industry initiative that aims to implement the root of trust in a hardware component, the trusted platform module. The initiative has been formalized in a set of specifications and is currently at version 1.2. Cloud computing platforms pool virtualized computing, storage and network resources in order to serve a large number of customers customers that use a multi-tenant multiplexing model to offer on-demand self-service over broad network. Open source cloud computing platforms are, similar to trusted computing, a fairly recent technology in active development. The issue of trust in public cloud environments is addressed by examining the state of the art within cloud computing security and subsequently addressing the issues of establishing trust in the launch of a generic virtual machine in a public cloud environment. As a result, the thesis proposes a trusted launch protocol that allows CS clients to verify and ensure the integrity of the VM instance at launch time, as well as the integrity of the host where the VM instance is launched. The protocol relies on the use of Trusted Platform Module (TPM) for key generation and data protection. The TPM also plays an essential part in the integrity attestation of the VM instance host. Along with a theoretical, platform-agnostic protocol, the thesis also describes a detailed implementation design of the protocol using the OpenStack cloud computing platform. In order the verify the implementability of the proposed protocol, a prototype implementation has built using a distributed deployment of OpenStack. While the protocol covers only the trusted launch procedure using generic virtual machine images, it presents a step aimed to contribute towards the creation of a secure and trusted public cloud computing environment

Cloud Security : A Review of Recent Threats and Solution Models

The most significant barrier to the wide adoption of cloud services has been attributed to perceived cloud insecurity (Smitha, Anna and Dan, 2012). In an attempt to review this subject, this paper will explore some of the major security threats to the cloud and the security models employed in tackling them. Access control violations, message integrity violations, data leakages, inability to guarantee complete data deletion, code injection, malwares and lack of expertise in cloud technology rank the major threats. The European Union invested €3m in City University London to research into the certification of Cloud security services. This and more recent developments are significant in addressing increasing public concerns regarding the confidentiality, integrity and privacy of data held in cloud environments. Some of the current cloud security models adopted in addressing cloud security threats were – Encryption of all data at storage and during transmission. The Cisco IronPort S-Series web security appliance was among security solutions to solve cloud access control issues. 2-factor Authentication with RSA SecurID and close monitoring appeared to be the most popular solutions to authentication and access control issues in the cloud. Database Active Monitoring, File Active Monitoring, URL Filters and Data Loss Prevention were solutions for detecting and preventing unauthorised data migration into and within clouds. There is yet no guarantee for a complete deletion of data by cloud providers on client requests however; FADE may be a solution (Yang et al., 2012)