Improved Kernel Security Through Code Validation, Diversification, and Minimization

The vast majority of hosts on the Internet, including mobile clients, are running one of three commodity, general-purpose operating system families. In such operating systems the kernel software executes at the highest processor privilege level. If an adversary is able to hijack the kernel software then by extension he has full control of the system. This control includes the ability to disable protection mechanisms and hide evidence of compromise. The lack of diversity in commodity, general-purpose operating systems enables attackers to craft a single kernel exploit that has the potential to infect millions of hosts. If enough variants of the vulnerable software exist, then mass exploitation is much more difficult to achieve. We introduce novel kernel diversification techniques to improve kernel security. Many modern kernels are self-patching; they modify themselves at run-time. Self-patching kernels must therefore allow kernel code to be modified at run-time. To prevent code injection attacks, some operating systems and security mechanisms enforce a W^X memory protection policy for kernel code. This protection policy prevents self-patching kernels from applying patches at run-time. We introduce a novel run-time kernel instruction-level validation technique to validate the integrity of patches at run-time. Kernels shipped with general-purpose operating systems often contain extraneous code. The code may contain exploitable vulnerabilities or may be pieced together using return/jump-oriented programming to attack the system. Code-injection prevention techniques do not prevent such attacks. We introduce a novel run-time kernel minimization technique to improve kernel security. We show that it is possible to strengthen the defenses of commodity general-purpose computer operating systems by increasing the diversity of, validating the integrity of, and ensuring the minimality of the included kernel components without modifying the kernel source code. Such protections can therefore be added to existing widely-used unmodified operating systems to prevent malicious software from executing in supervisor mode

IntRepair: Informed Repairing of Integer Overflows

Integer overflows have threatened software applications for decades. Thus, in this paper, we propose a novel technique to provide automatic repairs of integer overflows in C source code. Our technique, based on static symbolic execution, fuses detection, repair generation and validation. This technique is implemented in a prototype named IntRepair. We applied IntRepair to 2,052C programs (approx. 1 million lines of code) contained in SAMATE's Juliet test suite and 50 synthesized programs that range up to 20KLOC. Our experimental results show that IntRepair is able to effectively detect integer overflows and successfully repair them, while only increasing the source code (LOC) and binary (Kb) size by around 1%, respectively. Further, we present the results of a user study with 30 participants which shows that IntRepair repairs are more than 10x efficient as compared to manually generated code repairsComment: Accepted for publication at the IEEE TSE journal. arXiv admin note: text overlap with arXiv:1710.0372

Neutral Networks of Real-World Programs and their Application to Automated Software Evolution

The existing software development ecosystem is the product of evolutionary forces, and consequently real-world software is amenable to improvement through automated evolutionary techniques. This dissertation presents empirical evidence that software is inherently robust to small randomized program transformations, or \u27mutations. Simple and general mutation operations are demonstrated that can be applied to software source code, compiled assembler code, or directly to binary executables. These mutations often generate variants of working programs that differ significantly from the original, yet remain fully functional. Applying successive mutations to the same software program uncovers large \u27neutral networks\u27 of fully functional variants of real-world software projects. These properties of \u27mutational robustness\u27 and the corresponding \u27neutral networks\u27 have been studied extensively in biology and are believed to be related to the capacity for unsupervised evolution and adaptation. As in biological systems, mutational robustness and neutral networks in software systems enable automated evolution. The dissertation presents several applications that leverage software neutral networks to automate common software development and maintenance tasks. Neutral networks are explored to generate diverse implementations of software for improving runtime security and for proactively repairing latent bugs. Next, a technique is introduced for automatically repairing bugs in the assembler and executables compiled from off-the-shelf software. As demonstration, a proprietary executable is manipulated to patch security vulnerabilities without access to source code or any aid from the software vendor. Finally, software neutral networks are leveraged to optimize complex nonfunctional runtime properties. This optimization technique is used to reduce the energy consumption of the popular PARSEC benchmark applications by 20% as compared to the best available public domain compiler optimizations. The applications presented herein apply evolutionary computation techniques to existing software using common software engineering tools. By enabling evolutionary techniques within the existing software development toolchain, this work is more likely to be of practical benefit to the developers and maintainers of real-world software systems

Automatic Software Repair: a Bibliography

This article presents a survey on automatic software repair. Automatic software repair consists of automatically finding a solution to software bugs without human intervention. This article considers all kinds of repairs. First, it discusses behavioral repair where test suites, contracts, models, and crashing inputs are taken as oracle. Second, it discusses state repair, also known as runtime repair or runtime recovery, with techniques such as checkpoint and restart, reconfiguration, and invariant restoration. The uniqueness of this article is that it spans the research communities that contribute to this body of knowledge: software engineering, dependability, operating systems, programming languages, and security. It provides a novel and structured overview of the diversity of bug oracles and repair operators used in the literature

Chain-of-Thought Prompting of Large Language Models for Discovering and Fixing Software Vulnerabilities

Security vulnerabilities are increasingly prevalent in modern software and they are widely consequential to our society. Various approaches to defending against these vulnerabilities have been proposed, among which those leveraging deep learning (DL) avoid major barriers with other techniques hence attracting more attention in recent years. However, DL-based approaches face critical challenges including the lack of sizable and quality-labeled task-specific datasets and their inability to generalize well to unseen, real-world scenarios. Lately, large language models (LLMs) have demonstrated impressive potential in various domains by overcoming those challenges, especially through chain-of-thought (CoT) prompting. In this paper, we explore how to leverage LLMs and CoT to address three key software vulnerability analysis tasks: identifying a given type of vulnerabilities, discovering vulnerabilities of any type, and patching detected vulnerabilities. We instantiate the general CoT methodology in the context of these tasks through VSP , our unified, vulnerability-semantics-guided prompting approach, and conduct extensive experiments assessing VSP versus five baselines for the three tasks against three LLMs and two datasets. Results show substantial superiority of our CoT-inspired prompting (553.3%, 36.5%, and 30.8% higher F1 accuracy for vulnerability identification, discovery, and patching, respectively, on CVE datasets) over the baselines. Through in-depth case studies analyzing VSP failures, we also reveal current gaps in LLM/CoT for challenging vulnerability cases, while proposing and validating respective improvements

Implementation of IS Security Standards on Pharmaceutical Manufacturing

This thesis addresses the issue of Information Systems (IS) security in pharmaceutical manufacturing which is closely related to the ISA 99 standard. The ISA 99 'Security for industrial Automation and Control Systems' standard is focused on the work for securing process automation systems from IS security threats. The main thought behind the ISA 99 standard is that a high level of IS security in computerized manufacturing environments cannot be achieved through just one project but needs long-term dedication. Therefore the ISA 99 standard suggests the implementation of an IS security program as the best way to reduce IS security risks to process automation systems and to sustain risk reduction over time. The overall objective of the study was to suggest an IS security program suitable for the pharmaceutical manufacturing at the AstraZeneca manufacturing and supply site in Södertälje, Sweden. The suggested IS security program can briefly be described as a long-term strategy for how to perform IS security activities in the manufacturing at the Södertälje site. The security program defines both technical and organizational requirements and recommendations. According to the ISA 99 standard, working with IS security in the process automation systems environment require both technical, cultural and organizational perspectives. The suggested security program therefore recommends the forming of a special group for working with IS security in the manufacturing within Sweden Operations. This group includes employees from different departments such as IS security, IS/IT, process automation systems managers, engineering, operators and managers in production areas as well as quality assurance personnel. The purpose with the group is to make the IS security work more effective through reducing bureaucracy, increasing communication and sharing of knowledge and business perspectives. The security program also presents IS security policies for the production at the Södertälje site. A security policy is a written document or directive that defines how the organization defines and operates IS security in the process automation systems environment. The security policy ensures both management support and understanding of roles and responsibilities for IS security in the process automation systems environment