De manière générale, en informatique, les vulnérabilités logicielles sont définies comme des cas particuliers de fonctionnements non attendus du système menant à la dégradation des propriétés de sécurité ou à la violation de la politique de sécurité. Ces vulnérabilités peuvent être exploitées par des utilisateurs malveillants comme brèches de sécurité. Comme la documentation sur les vulnérabilités n'est pas toujours disponible pour les développeurs et que les outils qu'ils utilisent ne leur permettent pas de les détecter et les éviter, l'industrie du logiciel continue à être paralysée par des failles de sécurité. Nos travaux de recherche s'inscrivent dans le cadre du projet Européen SHIELDS et portent sur les techniques de modélisation et de détection formelles de vulnérabilités. Dans ce domaine, les approches existantes sont peu nombreuses et ne se basent pas toujours sur une modélisation formelle précise des vulnérabilités qu'elles traitent. De plus, les outils de détection sous-jacents produisent un nombre conséquent de faux positifs/négatifs. Notons également qu'il est assez difficile pour un développeur de savoir quelles vulnérabilités sont détectées par chaque outil vu que ces derniers sont très peu documentés. En résumé, les contributions réalisées dans le cadre de cette thèse sont les suivantes: Définition d'un formalisme tabulaire de description de vulnérabilités appelé template. Définition d'un langage formel, appelé Condition de Détection de Vulnérabilité (VDC). Une approche de génération de VDCs à partir des templates. Définition d'une approche de détection de vulnérabilités combinant le model checking et l'injection de fautes. Évaluation des deux approches / In general, computer software vulnerabilities are defined as special cases where an unexpected behavior of the system leads to the degradation of security properties or the violation of security policies. These vulnerabilities can be exploited by malicious users or systems impacting the security and/or operation of the attacked system. Since the literature on vulnerabilities is not always available to developers and the used tools do not allow detecting and avoiding them; the software industry continues to be affected by security breaches. Therefore, the detection of vulnerabilities in software has become a major concern and research area. Our research was done under the scope of the SHIELDS European project and focuses specifically on modeling techniques and formal detection of vulnerabilities. In this area, existing approaches are limited and do not always rely on a precise formal modeling of the vulnerabilities they target. Additionally detection tools produce a significant number of false positives/negatives. Note also that it is quite difficult for a developer to know what vulnerabilities are detected by each tool because they are not well documented. Under this context the contributions made in this thesis are: Definition of a formalism called template. Definition of a formal language, called Vulnerability Detection Condition (VDC), which can accurately model the occurrence of a vulnerability. Also a method to generate VDCs from templates has been defined. Defining a second approach for detecting vulnerabilities which combines model checking and fault injection techniques. Experiments on both approaches

In general, computer software vulnerabilities are defined as special cases where an unexpected behavior of the system leads to the degradation of security properties or the violation of security policies. These vulnerabilities can be exploited by malicious users or systems impacting the security and/or operation of the attacked system. Since the literature on vulnerabilities is not always available to developers and the used tools do not allow detecting and avoiding them; the software industry continues to be affected by security breaches. Therefore, the detection of vulnerabilities in software has become a major concern and research area. Our research was done under the scope of the SHIELDS European project and focuses specifically on modeling techniques and formal detection of vulnerabilities. In this area, existing approaches are limited and do not always rely on a precise formal modeling of the vulnerabilities they target. Additionally detection tools produce a significant number of false positives/negatives. Note also that it is quite difficult for a developer to know what vulnerabilities are detected by each tool because they are not well documented. Under this context the contributions made in this thesis are: Definition of a formalism called template. Definition of a formal language, called Vulnerability Detection Condition (VDC), which can accurately model the occurrence of a vulnerability. Also a method to generate VDCs from templates has been defined. Defining a second approach for detecting vulnerabilities which combines model checking and fault injection techniques. Experiments on both approaches