Automated detection, explanation, and remediation of security inconsistencies in Web application access controls using program analysis

该研究旨在提高软件的质量和安全完整性，同时从应用安全的角度降低其开发成本。 当今Web和移动的应用程序、云服务和网络物理系统的大规模部署需要频繁且短的发布周期或连续发布。这给一般质量保证和应用程序安全带来了更大的压力和时间限制。 我建议设计，实施和评估自动化和可扩展的方法，在软件应用程序中的访问控制的早期故障定位和自动修复的安全不一致性和可扩展性。 我建议通过调查安全模型中违反策略的反例来定位错误的安全代码，并合成人类可用的解释。 在这个建议中，我想解决和调查的自动修复检测到的安全不一致的推理本地化的故障，对应于违反一些角色特权政策的执行。 例如，可以通过自动插入适当的授权检查来修复丢失的检查，以恢复所需的安全可达性和对安全敏感资源的访问。 在寻求基于路径的安全修复时会出现两个问题： (a)选择要插入、删除或修改的实现适当安全检查的代码片段，以修复检测到的不一致。 (b)沿着可能违反安全可达性约束的许多路径在何处插入检查沿着。 在这个建议中，我想首先解决自动安全修复的问题，其次解决所需新安全检查的最佳位置问题。 我想确定可以自动修复的安全问题的类别，从而减轻开发人员的负担。 我想研究它们在大型工业或开源系统中的重要性。 当自动化不能完全实现一些不一致的类别，我想调查一个互动的和基于解释的策略，以支持开发人员在他们的手动修复不一致的解释和建议。 拟议的自动修复研究将防止发现和修复的不一致被释放。软件系统将更安全，更不易受到攻击。从检测到修复发布的整个过程将更短。因此，攻击的机会之窗将大大减少。 研究结果将为研究人员从安全的角度自动分析和修复大型应用程序提供方法和工具。还将产生关于大型和流行的开源应用程序中自动检测和修复不一致性的有效性的调查结果。

The proposed research aims at improving the quality and the security integrity of software, while reducing its development cost in the perspective of application security. Today's large deployment of Web and mobile applications, cloud services, and cyber-physical systems demand frequent and short release cycles or continuous releases. This puts even more stress and time constraints on quality assurance in general and on application security. I propose to design, implement, and evaluate automated and scalable methods for the early fault localization and automated repair of security inconsistencies and vulnerabilties in access controls in software applications. I propose to localize faulty security code by investigating counter-examples from violated policies in security models and to synthesize human-usable explanations. In this proposal, I want to address and investigate the automated repair of detected security inconsistencies by reasoning on the localized faults that correspond to executions that violate some role-privilege policies. For example, missing checks could be repaired by automatically inserting proper authorization checks to restore the desired security reachability and accesses to security sensitive resources. Two problems appear when path based security repair is sought: (a) selection of code fragments implementing appropriate security checks to be inserted, deleted, or modified to repair the detected inconsistencies. (b) where to insert the checks along the possibly many paths that violate the security reachability constraints. In this proposal, I want to address first the problem of automated security repairs and second the problem of optimal placement of required new security checks. I want to determine the categories of security problems that can be automatically repaired, thus relieving the developers from this burden. I want to investigate their significance in large industrial or open source systems. When automation cannot be completely achieved for some inconsistency category, I want to investigate an interactive and recommendation-based strategy to support the developers during their manual repair of inconsistencies by supplying explanations and suggestions. The proposed research on automated repairs will prevent detected and repaired inconsistencies from being released. Software systems will be more secure and less vulnerable to attacks. The overall process from detection to repaired release will be shorter. Therefore, the window of opportunity for attacks will be dramatically reduced. Results from this research will be methods and tools available to researchers for automatically analyzing and repairing large applications in the perspective of security. Findings about the effectiveness of automated detection and repair of inconsistencies in large and popular open source applications will also be produced.