Posted by Jeff Vander Stoep – Android team, and Alex Rebert – Security Foundations

Memory safety vulnerabilities remain a pervasive threat to software security. At Google, we believe the path to eliminating this class of vulnerabilities at scale and building high-assurance software lies in Safe Coding, a secure-by-design approach that prioritizes transitioning to memory-safe languages.

This post demonstrates why focusing on Safe Coding for new code quickly and counterintuitively reduces the overall security risk of a codebase, finally breaking through the stubbornly high plateau of memory safety vulnerabilities and starting an exponential decline, all while being scalable and cost-effective.

We’ll also share updated data on how the percentage of memory safety vulnerabilities in Android dropped from 76% to 24% over 6 years as development shifted to memory safe languages.

Counterintuitive results

Consider a growing codebase primarily written in memory-unsafe languages, experiencing a constant influx of memory safety vulnerabilities. What happens if we gradually transition to memory-safe languages for new features, while leaving existing code mostly untouched except for bug fixes?

We can simulate the results. After some years, the code base has the following makeup¹ as new memory unsafe development slows down, and new memory safe development starts to take over:

In the final year of our simulation, despite the growth

[…]
Content was cut in order to protect the source.Please visit the source for the rest of the article.