Since the advent of SPECTRE, a number of countermeasures have been proposed and deployed. Rigorously reasoning about their effectiveness, however, requires a well-defined notion of security against speculative execution attacks, which has been missing until now.In this paper (1) we put forward speculative non-interference, the first semantic notion of security against speculative execution attacks, and (2) we develop SPECTECTOR, an algorithm based on symbolic execution to automatically prove speculative noninterference, or to detect violations.We implement SPECTECTOR in a tool, which we use to detect subtle leaks and optimizations opportunities in the way major compilers place SPECTRE countermeasures. A scalability analysis indicates that checking speculative non-interference does not exhibit fundamental bottlenecks beyond those inherited by symbolic execution.

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Security-Aware Query Processing is the problem of computing answers to queries in the presence of access control policies. We present general impossibility results for the existence of optimal algorithms for Security-Aware Query Processing and classify query languages for which such algorithms exist. In particular, we show that for the relational calculus there are no optimal algorithms, whereas optimal algorithms exist for some of its fragments, such as the existential fragment.We also establish relationships between two different models of Fine-Grained Access Control, called Truman and NonTruman models, which have been previously presented in the literature as distinct. For optimal Security-Aware Query Processing, we show that the Non-Truman model is a special case of the Truman model for boolean queries in the relational calculus, moreover the two models coincide for more powerful languages, such as the relational calculus with aggregation operators. In contrast, these two models are distinct for non-boolean queries.

Databases can leak confidential information when users combine query results with probabilistic data dependencies and prior knowledge. Current research offers mechanisms that either handle a limited class of dependencies or lack tractable enforcement algorithms. We propose a foundation for Database Inference Control based on PROBLOG, a probabilistic logic programming language. We leverage this foundation to develop ANGERONA, a provably secure enforcement mechanism that prevents information leakage in the presence of probabilistic dependencies. We then provide a tractable inference algorithm for a practically relevant fragment of PROBLOG. We empirically evaluate ANGERONA's performance showing that it scales to relevant security-critical problems.

We show how to infer deterministic cache replacement policies using off-the-shelf automata learning and program synthesis techniques. For this, we construct and chain two abstractions that expose the cache replacement policy of any set in the cache hierarchy as a membership oracle to the learning algorithm, based on timing measurements on a silicon CPU. Our experiments demonstrate an advantage in scope and scalability over prior art and uncover 2 previously undocumented cache replacement policies.

Abstract. One of the current core requirements of web applications is the continuity of the service, because loss in availability can lead to severe economic losses. This is the main reason behind the growing interest in web application testing that oers to researchers several challenges, due to the peculiar nature of these applications. Several classical testing techniques have been extended to deal with web testing. In this paper we propose to extend to web application testing a recent search-based approach that optimizes the generation of the whole test suite. This approach has several advantages over common approaches that optimize the generation of a single test case at a time. We show the technological challenges we have had to face, the architecture of the tool WETT we have developed, and some preliminary results of the experiments.

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Existing SQL access control mechanisms are extremely limited. Attackers can leak information and escalate their privileges using advanced database features such as views, triggers, and integrity constraints. This is not merely a problem of vendors lagging behind the state-of-the-art. The theoretical foundations for database security lack adequate security definitions and a realistic attacker model, both of which are needed to evaluate the security of modern databases. We address these issues and present a provably secure access control mechanism that prevents attacks that defeat popular SQL database systems.Comment: A short version of this paper has been published in the proceedings of the 1st IEEE European Symposium on Security and Privacy (EuroS&P 2016