Rust Now: A CISO's Case for Memory Safe Software

Posted: March 27, 2026 to Cybersecurity.

Rust Now: A CISO's Case for Memory Safe Software

Approximately 70 percent of all security vulnerabilities in large codebases stem from memory safety issues. This statistic, independently confirmed by Microsoft, Google, and the NSA, represents the single largest category of exploitable software defects. Buffer overflows, use-after-free bugs, null pointer dereferences, double frees, and data races account for the majority of critical CVEs published each year and the overwhelming majority of zero-day exploits observed in the wild.

As a CISO, you cannot patch your way out of a systemic language-level problem. Every month brings new memory corruption CVEs in software your organization depends on, each requiring emergency patches, downtime, and incident response resources. The argument for memory-safe languages has moved from academic theory to operational risk management. National security agencies, major tech companies, and federal policy makers have all reached the same conclusion: we must stop writing new code in memory-unsafe languages.

The Scale of the Memory Safety Problem

The data is unambiguous across multiple independent sources:

• Microsoft reported that 70% of their security patches between 2006 and 2018 addressed memory safety bugs in C and C++ code
• Google found that 67% of zero-day exploits observed in the wild in 2021 were memory corruption vulnerabilities, rising to 75% in Chrome specifically
• Android's memory safety vulnerability rate dropped from 76% to 24% of total vulnerabilities between 2019 and 2023 as the percentage of new code written in Rust increased
• The CISA and NSA joint advisory explicitly recommends organizations create memory-safe language roadmaps
• The White House Office of the National Cyber Director published a report in February 2024 calling for the adoption of memory-safe programming languages as a national security priority

Every C or C++ codebase in your organization carries this risk inherently. Not because your developers are careless, but because these languages require programmers to manually manage memory allocation and deallocation. Humans make mistakes under pressure, at scale, and across millions of lines of code. The error rate is not zero and never will be.

Why Rust Specifically

Several memory-safe languages exist: Go, Java, C#, Python, Swift, Kotlin. Each eliminates memory safety bugs. Rust occupies a unique position in this landscape because it provides memory safety without garbage collection, making it suitable for the domains where C and C++ are currently entrenched:

• Zero-cost abstractions: Rust compiles to native machine code with performance comparable to optimized C and C++. There is no runtime overhead from safety checks because safety is enforced at compile time, not at runtime.
• No garbage collection: Unlike Go, Java, or C#, Rust does not pause execution for garbage collection. This is critical for real-time systems, embedded devices, operating system kernels, network stacks, and any application where predictable latency matters.
• Compile-time memory safety: The Rust compiler's ownership and borrow checking system prevents memory safety violations before code ever runs. If the program compiles, entire classes of bugs (use-after-free, double-free, buffer overflow, data races) are structurally impossible.
• Concurrency without data races: Rust's type system prevents data races at compile time. Concurrent code that would silently corrupt shared memory in C++ will not compile in Rust. The compiler forces you to handle shared state correctly.
• Interoperability: Rust has first-class C FFI (Foreign Function Interface) support, allowing gradual migration of individual components without rewriting entire applications.

Production Adoption: Who Is Using Rust

Rust is no longer experimental. It is running in the most security-critical and performance-sensitive systems in production:

• Linux kernel: Rust is an officially supported language for kernel development as of Linux 6.1
• Android: Google uses Rust for new Android platform code, and memory vulnerabilities have dropped proportionally
• Windows: Microsoft is rewriting core Windows components in Rust, starting with the kernel
• AWS: Firecracker (the microVM engine behind Lambda and Fargate) is written entirely in Rust
• Cloudflare: Performance-critical edge services are written in Rust
• Discord: Replaced Go services with Rust for 10x latency improvement
• 1Password: Core cryptographic engine rewritten in Rust for cross-platform memory safety

The Business Case for CISOs

Translating memory safety into the risk language that boards and executives understand:

Reduced vulnerability surface: Eliminating 70% of the most common vulnerability class from new code means fewer emergency patches, fewer incident response cycles, fewer potential breach vectors, and a measurably smaller attack surface over time.

Lower remediation costs: The industry consensus is that fixing a vulnerability discovered in production costs 6 to 30 times more than finding it during development. Rust moves memory safety violation detection to compile time, where the cost of remediation is effectively zero, developers simply fix the code until it compiles.

Compliance alignment: Frameworks like CMMC, NIST 800-53, and NIST SSDF (Secure Software Development Framework) require secure development practices. Demonstrating the use of memory-safe languages is a concrete, auditable control that satisfies multiple requirements simultaneously.

Supply chain risk reduction: Software supply chain attacks frequently exploit memory corruption vulnerabilities in widely-used libraries. Requiring or encouraging memory-safe languages in your software supply chain, both internal development and vendor assessments, reduces upstream risk.

Cyber insurance positioning: Insurers increasingly evaluate software development practices. Demonstrating a memory-safe language strategy strengthens your risk profile and may influence premium calculations.

A Practical Roadmap for Adoption

No reasonable CISO would propose rewriting the entire codebase in Rust overnight. The practical approach is incremental, risk-prioritized, and aligned with natural software lifecycle events:

1. New projects (immediate): Default to Rust or another memory-safe language for all new development. Require a documented technical justification (not preference) for any new code written in C or C++.
2. Security-critical components (6-12 months): Identify parsers, protocol handlers, cryptographic implementations, authentication modules, and network-facing code. These process untrusted input and represent the highest-risk code paths. Prioritize rewriting these in Rust at the next major version or during planned refactoring.
3. FFI boundaries (ongoing): Rust can be called from C/C++ and vice versa through its FFI. Wrap high-risk C functions and modules in safe Rust interfaces without rewriting entire applications. This is the lowest-cost, highest-impact migration strategy.
4. Build system and CI/CD requirements (3-6 months): Update your secure development lifecycle (SDL) to require memory safety justification for any new C or C++ code. Add Rust-compatible tooling to your CI/CD pipelines (cargo clippy for linting, cargo audit for dependency vulnerability scanning).
5. Vendor requirements (12+ months): Include memory-safe language preference in vendor security assessments and procurement requirements. This signals market demand and reduces your supply chain risk over time.

Addressing Common Objections

"Our developers don't know Rust." Rust has a learning curve, particularly around the ownership and borrowing concepts. However, the language is exceptionally well-documented, has an active community, and includes excellent compiler error messages that guide developers toward correct code. Most experienced C++ developers become productive in Rust within 2 to 3 months. The training investment pays for itself in reduced vulnerability remediation costs within the first year.

"Rust is too new and unproven." Rust reached 1.0 stability in 2015 and has maintained a 6-week release cycle with strong backward compatibility ever since. The Linux kernel, Android, Windows, AWS, and Cloudflare running Rust in production represents billions of users depending on Rust code daily. The ecosystem has over 140,000 packages on crates.io.

"Our legacy code works fine." Your legacy code works fine until it does not. Every buffer overflow in a C library is a vulnerability waiting to be discovered. The question is not whether memory corruption bugs exist in your C/C++ code but whether attackers find them before your team does. Historical data shows they frequently do.

"The performance overhead is not worth it." Rust has zero runtime performance overhead compared to C/C++. In many benchmarks, Rust matches or exceeds C++ performance because the compiler can make more aggressive optimizations when it has provable memory safety information.

Measuring Progress

Track these metrics to demonstrate value and maintain executive support:

• Percentage of new code written in memory-safe languages (target: 100% within 2 years for new projects)
• Number of memory safety CVEs in your codebase (should trend toward zero for new code)
• Patch cycle frequency for memory-related vulnerabilities vs. other vulnerability types
• Time spent on memory-safety-related incident response (should decrease quarter over quarter)
• Developer productivity metrics comparing Rust and C++ projects (Rust typically shows fewer production bugs)

Integrating memory safety metrics into your broader cybersecurity program reporting ensures visibility at the executive level and ties engineering decisions directly to business risk reduction.

Frequently Asked Questions