Modern systems are mainly composed of IoT devices and Smartphones. Most of these devices use ARM processors, which, along with flexible licensing, have new security architecture features, such as ARM TrustZone, that enables execution of a secure application in an untrusted environment. Furthermore, with well-supported, extensible, open-source embedded operating systems like Android allows the manufactures to quickly customize their operating system with device drivers, thus reducing the time-to-market. Unfortunately, the proliferation of device vendors and race to the market has resulted in poor quality device drivers containing critical security vulnerabilities. Furthermore, the patches for these vulnerabilities get merged into the end-products with a significant delay resulting in the Patch Gap, which causes privacy and security of billions of users to be at risk.

In this dissertation, I will show how the new architecture features can lead to security issues by introducing new attack vectors. Second, I will show that the existing techniques are inadequate to find the security issues in Linux kernel drivers and how, with certain well-defined optimizations, we can precisely find security issues. Third, I will present my solution to the problem of Patch Gap by showing a principled approach to automatically port patches to vendor product repositories.

Finally, I will present our on-going work to automatically port C to Checked C, which provides a low overhead, backward-compatible, and memory-safe C alternative that could be used on resource-constrained modern systems to prevent security vulnerabilities. Through this work, I presented effective ways to find, fix, propagate, and prevent vulnerabilities in modern system software, thus improving modern systems security.