Vulnerability detection in device drivers

Tese de doutoramento, Informática (Ciência da Computação), Universidade de Lisboa, Faculdade de Ciências, 2017The constant evolution in electronics lets new equipment/devices to be regularly made available on the market, which has led to the situation where common operating systems (OS) include many device drivers(DD) produced by very diverse manufactures. Experience has shown that the development of DD is error prone, as a majority of the OS crashes can be attributed to flaws in their implementation. This thesis addresses the challenge of designing methodologies and tools to facilitate the detection of flaws in DD, contributing to decrease the errors in this kind of software, their impact in the OS stability, and the security threats caused by them. This is especially relevant because it can help developers to improve the quality of drivers during their implementation or when they are integrated into a system. The thesis work started by assessing how DD flaws can impact the correct execution of the Windows OS. The employed approach used a statistical analysis to obtain the list of kernel functions most used by the DD, and then automatically generated synthetic drivers that introduce parameter errors when calling a kernel function, thus mimicking a faulty interaction. The experimental results showed that most targeted functions were ineffective in the defence of the incorrect parameters. A reasonable number of crashes and a small number of hangs were observed suggesting a poor error containment capability of these OS functions. Then, we produced an architecture and a tool that supported the automatic injection of network attacks in mobile equipment (e.g., phone), with the objective of finding security flaws (or vulnerabilities) in Wi-Fi drivers. These DD were selected because they are of easy access to an external adversary, which simply needs to create malicious traffic to exploit them, and therefore the flaws in their implementation could have an important impact. Experiments with the tool uncovered a previously unknown vulnerability that causes OS hangs, when a specific value was assigned to the TIM element in the Beacon frame. The experiments also revealed a potential implementation problem of the TCP-IP stack by the use of disassociation frames when the target device was associated and authenticated with a Wi-Fi access point. Next, we developed a tool capable of registering and instrumenting the interactions between a DD and the OS. The solution used a wrapper DD around the binary of the driver under test, enabling full control over the function calls and parameters involved in the OS-DD interface. This tool can support very diverse testing operations, including the log of system activity and to reverse engineer the driver behaviour. Some experiments were performed with the tool, allowing to record the insights of the behaviour of the interactions between the DD and the OS, the parameter values and return values. Results also showed the ability to identify bugs in drivers, by executing tests based on the knowledge obtained from the driver’s dynamics. Our final contribution is a methodology and framework for the discovery of errors and vulnerabilities in Windows DD by resorting to the execution of the drivers in a fully emulated environment. This approach is capable of testing the drivers without requiring access to the associated hardware or the DD source code, and has a granular control over each machine instruction. Experiments performed with Off the Shelf DD confirmed a high dependency of the correctness of the parameters passed by the OS, identified the precise location and the motive of memory leaks, the existence of dormant and vulnerable code.A constante evolução da eletrónica tem como consequência a disponibilização regular no mercado de novos equipamentos/dispositivos, levando a uma situação em que os sistemas operativos (SO) mais comuns incluem uma grande quantidade de gestores de dispositivos (GD) produzidos por diversos fabricantes. A experiência tem mostrado que o desenvolvimento dos GD é sujeito a erros uma vez que a causa da maioria das paragens do SO pode ser atribuída a falhas na sua implementação. Esta tese centra-se no desafio da criação de metodologias e ferramentas que facilitam a deteção de falhas nos GD, contribuindo para uma diminuição nos erros neste tipo de software, o seu impacto na estabilidade do SO, e as ameaças de segurança por eles causadas. Isto é especialmente relevante porque pode ajudar a melhorar a qualidade dos GD tanto na sua implementação como quando estes são integrados em sistemas. Este trabalho inicia-se com uma avaliação de como as falhas nos GD podem levar a um funcionamento incorreto do SO Windows. A metodologia empregue usa uma análise estatística para obter a lista das funções do SO que são mais utilizadas pelos GD, e posteriormente constrói GD sintéticos que introduzem erros nos parâmetros passados durante a chamada às funções do SO, e desta forma, imita a integração duma falta. Os resultados das experiências mostraram que a maioria das funções testadas não se protege eficazmente dos parâmetros incorretos. Observou-se a ocorrência de um número razoável de paragens e um pequeno número de bloqueios, o que sugere uma pobre capacidade das funções do SO na contenção de erros. Posteriormente, produzimos uma arquitetura e uma ferramenta que suporta a injeção automática de ataques em equipamentos móveis (e.g., telemóveis), com o objetivo de encontrar falhas de segurança (ou vulnerabilidades) em GD de placas de rede Wi-Fi. Estes GD foram selecionados porque são de fácil acesso a um atacante remoto, o qual apenas necessita de criar tráfego malicioso para explorar falhas na sua implementação podendo ter um impacto importante. As experiências realizadas com a ferramenta revelaram uma vulnerabilidade anteriormente desconhecida que provoca um bloqueio no SO quando é atribuído um valor específico ao campo TIM da mensagem de Beacon. As experiências também revelaram um potencial problema na implementação do protocolo TCP-IP no uso das mensagens de desassociação quando o dispositivo alvo estava associado e autenticado com o ponto de acesso Wi-Fi. A seguir, desenvolvemos uma ferramenta com a capacidade de registar e instrumentar as interações entre os GD e o SO. A solução usa um GD que envolve o código binário do GD em teste, permitindo um controlo total sobre as chamadas a funções e aos parâmetros envolvidos na interface SO-GD. Esta ferramenta suporta diversas operações de teste, incluindo o registo da atividade do sistema e compreensão do comportamento do GD. Foram realizadas algumas experiências com esta ferramenta, permitindo o registo das interações entre o GD e o SO, os valores dos parâmetros e os valores de retorno das funções. Os resultados mostraram a capacidade de identificação de erros nos GD, através da execução de testes baseados no conhecimento da dinâmica do GD. A nossa contribuição final é uma metodologia e uma ferramenta para a descoberta de erros e vulnerabilidades em GD Windows recorrendo à execução do GD num ambiente totalmente emulado. Esta abordagem permite testar GD sem a necessidade do respetivo hardware ou o código fonte, e possuí controlo granular sobre a execução de cada instrução máquina. As experiências realizadas com GD disponíveis comercialmente confirmaram a grande dependência que os GD têm nos parâmetros das funções do SO, e identificaram o motivo e a localização precisa de fugas de memória, a existência de código não usado e vulnerável

Security techniques for sensor systems and the Internet of Things

Sensor systems are becoming pervasive in many domains, and are recently being generalized by the Internet of Things (IoT). This wide deployment, however, presents significant security issues. We develop security techniques for sensor systems and IoT, addressing all security management phases. Prior to deployment, the nodes need to be hardened. We develop nesCheck, a novel approach that combines static analysis and dynamic checking to efficiently enforce memory safety on TinyOS applications. As security guarantees come at a cost, determining which resources to protect becomes important. Our solution, OptAll, leverages game-theoretic techniques to determine the optimal allocation of security resources in IoT networks, taking into account fixed and variable costs, criticality of different portions of the network, and risk metrics related to a specified security goal. Monitoring IoT devices and sensors during operation is necessary to detect incidents. We design Kalis, a knowledge-driven intrusion detection technique for IoT that does not target a single protocol or application, and adapts the detection strategy to the network features. As the scale of IoT makes the devices good targets for botnets, we design Heimdall, a whitelist-based anomaly detection technique for detecting and protecting against IoT-based denial of service attacks. Once our monitoring tools detect an attack, determining its actual cause is crucial to an effective reaction. We design a fine-grained analysis tool for sensor networks that leverages resident packet parameters to determine whether a packet loss attack is node- or link-related and, in the second case, locate the attack source. Moreover, we design a statistical model for determining optimal system thresholds by exploiting packet parameters variances. With our techniques\u27 diagnosis information, we develop Kinesis, a security incident response system for sensor networks designed to recover from attacks without significant interruption, dynamically selecting response actions while being lightweight in communication and energy overhead

Component-based control system development for agile manufacturing machine systems

It is now a common sense that manufactures including machine suppliers and system integrators of the 21 st century will need to compete on global marketplaces, which are frequently shifting and fragmenting, with new technologies continuously emerging. Future production machines and manufacturing systems need to offer the "agility" required in providing responsiveness to product changes and the ability to reconfigure. The primary aim for this research is to advance studies in machine control system design, in the context of the European project VIR-ENG - "Integrated Design, Simulation and Distributed Control of Agile Modular Machinery"

Adaptive object management for distributed systems

This thesis describes an architecture supporting the management of pluggable software components and evaluates it against the requirement for an enterprise integration platform for the manufacturing and petrochemical industries. In a distributed environment, we need mechanisms to manage objects and their interactions. At the least, we must be able to create objects in different processes on different nodes; we must be able to link them together so that they can pass messages to each other across the network; and we must deliver their messages in a timely and reliable manner. Object based environments which support these services already exist, for example ANSAware(ANSA, 1989), DEC's Objectbroker(ACA,1992), Iona's Orbix(Orbix,1994)Yet such environments provide limited support for composing applications from pluggable components. Pluggability is the ability to install and configure a component into an environment dynamically when the component is used, without specifying static dependencies between components when they are produced. Pluggability is supported to a degree by dynamic binding. Components may be programmed to import references to other components and to explore their interfaces at runtime, without using static type dependencies. Yet thus overloads the component with the responsibility to explore bindings. What is still generally missing is an efficient general-purpose binding model for managing bindings between independently produced components. In addition, existing environments provide no clear strategy for dealing with fine grained objects. The overhead of runtime binding and remote messaging will severely reduce performance where there are a lot of objects with complex patterns of interaction. We need an adaptive approach to managing configurations of pluggable components according to the needs and constraints of the environment. Management is made difficult by embedding bindings in component implementations and by relying on strong typing as the only means of verifying and validating bindings. To solve these problems we have built a set of configuration tools on top of an existing distributed support environment. Specification tools facilitate the construction of independent pluggable components. Visual composition tools facilitate the configuration of components into applications and the verification of composite behaviours. A configuration model is constructed which maintains the environmental state. Adaptive management is made possible by changing the management policy according to this state. Such policy changes affect the location of objects, their bindings, and the choice of messaging system

Semantic Service Description Framework for Efficient Service Discovery and Composition

Web services have been widely adopted as a new distributed system technology by industries in the areas of, enterprise application integration, business process management, and virtual organisation. However, lack of semantics in current Web services standards has been a major barrier in the further improvement of service discovery and composition. For the last decade, Semantic Web Services have become an important research topic to enrich the semantics of Web services. The key objective of Semantic Web Services is to achieve automatic/semi-automatic Web service discovery, invocation, and composition. There are several existing semantic Web service description frameworks, such as, OWL-S, WSDL-S, and WSMF. However, existing frameworks have several issues, such as insufficient service usage context information, precisely specified requirements needed to locate services, lacking information about inter-service relationships, and insufficient/incomplete information handling, make the process of service discovery and composition not as efficient as it should be. To address these problems, a context-based semantic service description framework is proposed in this thesis. This framework focuses on not only capabilities of Web services, but also the usage context information of Web services, which we consider as an important factor in efficient service discovery and composition. Based on this framework, an enhanced service discovery mechanism is proposed. It gives service users more flexibility to search for services in more natural ways rather than only by technical specifications of required services. The service discovery mechanism also demonstrates how the features provided by the framework can facilitate the service discovery and composition processes. Together with the framework, a transformation method is provided to transform exiting service descriptions into the new framework based descriptions. The framework is evaluated through a scenario based analysis in comparison with OWL-S and a prototype based performance evaluation in terms of query response time, the precision and recall ratio, and system scalability