Google says its secure-by-design approach to code development has led to a significant reduction in memory safety vulnerabilities in Android and fewer risks to users.

The internet giant has been battling memory safety issues in both Android and Chrome for years, including by migrating them to memory-safe programming languages, such as Rust, and the effort has paid off, it says.

Memory safety bugs in Android have dropped from 76% in 2019 to 24% in 2024, and the decrease is expected to continue as the platform’s existing code base matures, while new code is developed using the memory-safe languages, Google says.

Given that most security defects reside in new or recently modified code, even if the amount of memory unsafe code in Android remains the same, the number of memory safety issues reduces as the code gets safer with time.

“Despite the majority of code still being unsafe (but, crucially, getting progressively older), we’re seeing a large and continued decline in memory safety vulnerabilities. We first reported this decline in 2022, and we continue to see the total number of memory safety vulnerabilities dropping,” Google notes.

The overall security risk to users has also decreased, as memory safety flaws are significantly more severe compared to other vulnerability types, and are more likely to be exploited remotely, the internet giant points out.

According to Google, the transition to memory-safe languages represents a major shift in approaching security, as reactive patching, proactive mitigations, and proactive vulnerability discovery failed to eliminate the root cause.

“The foundation of this shift is Safe Coding, which enforces security invariants directly into the development platform through language features, static analysis, and API design. The result is a secure-by-design ecosystem providing continuous assurance at scale, safe from the risk of accidentally introducing vulnerabilities,” Google says.

Moving forth, the internet giant will focus on interoperability, instead of throwing away existing memory-unsafe code and rewriting it all.

“The concept is simple: once we turn off the tap of new vulnerabilities, they decrease exponentially, making all of our code safer, increasing the effectiveness of security design, and alleviating the scalability challenges associated with existing memory safety strategies such that they can be applied more effectively in a targeted manner,” Google says.

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