Rust’s Role in Embedded Security 

However, memory safety is not the same as system security. Even with a memory safe language, an embedded device can be vulnerable to logic errors, incorrect assumptions about hardware behavior, unsafe abstractions, and flaws in trusted boundaries, which a compiler cannot prevent.  Rust reduces risk, but it does not remove the need for a more custom, targeted approach to testing. 

Public vulnerability data concerning Rust shows very few language-level issues. When vulnerabilities do occur, they are usually related to logical flow considerations, misconfigurations, or misuse of unsafe code, not flaws in the core language design. 

This inherent strength translates from the technical team to the C-suite because Rust demonstrably lowers the probability of certain failure modes. It improves code quality and reduces long-term maintenance risk. It is a strong foundation for building secure embedded products, but it is not a guarantee of security. 

What the Research Shows about Embedded Rust Risk 

While public exploit reports involving Rust-based embedded products are rare, academic research provides important insight into the real risk landscape. 

A 2024 peer reviewed study from Purdue University, titled “Rust for Embedded Systems: Current State and Open Problems” analyzed more than 6,400 embedded Rust crates. The researchers found that embedded Rust projects use unsafe code blocks, noted specifically by the named keyword, significantly more often than non-embedded Rust projects. In many cases, unsafe code is required to interact with hardware registers, DMA engines, interrupts, and vendor SDKs. It’s important to understand that unsafe doesn’t turn off the borrow checker or disable any of Rust’s other safety checks according to Rust’s official documentation. 

The study also found that existing static analysis and security tooling performed poorly on embedded Rust code. Build systems, cross compilation, and hardware-specific execution paths limit the effectiveness of automated analysis. 

This research supports the conclusion that even though Rust reduces memory safety risks, embedded Rust systems may still contain large areas of code that the compiler cannot fully reason about. These areas are precisely where logic errors and security flaws tend to appear and are human-introduced failures. 

The absence of public exploit disclosures should not be interpreted as proof of safety. Rust adoption in embedded products is still relatively new and has not yet been subjected to sustained public scrutiny. Additionally, security testing often happens privately, under non-disclosure agreements where findings are not published. In other words, lack of publicly available evidence is not proof of security. 

Focus on Logic-Based Flaws to Reduce Risk in Rust 

In short, and if you take away nothing else from this article, it’s this: Rust enforces how code uses memory allocations, but it does not require that the code implements the correct security logic. But why? Embedded devices depend on hardware behavior that exists outside the language model. Interrupt timing, peripheral configuration, debug interfaces, bootloaders, and update mechanisms all operate beyond the reach of the compiler. Many embedded Rust projects also rely on foreign function interfaces to C or vendor libraries, introducing additional trust boundaries. 

As a result, penetration testers could find vulnerabilities in Rust-based firmware that have nothing to do with memory corruption. The most common issues are logic-based. They arise from incorrect state handling, flawed assumptions, cryptographic misuse, and unsafe interactions with hardware. These types of logic-based flaws are what the remainder of this article intends to showcase. 

Examples of Logic-Based Vulnerabilities Found in Embedded Rust Systems 

1. Authentication Bypass Through Incorrect State Logic 

Embedded products frequently rely on internal state machines to control access to sensitive functionality. Examples include enabling debug features, accepting firmware updates, unlocking configuration menus, or transitioning into maintenance modes. Rust encourages modeling these workflows using enum, a custom data type used to define a set of named variables, which improves code clarity and reduces certain classes of bugs. However, Rust does not guarantee that the state machine enforces correct security logic. 

enum DeviceState { 
    Locked, 
    AwaitingAuth, 
    Unlocked, 
} 

impl DeviceState { 
    fn transition(self, cmd: u8) -> DeviceState { 
        match (self, cmd) { 
            (DeviceState::Locked, 0x01) => DeviceState::Unlocked, 
            (DeviceState::AwaitingAuth, 0x02) => DeviceState::Unlocked, 
            _ => self, 
        } 
    } 
} 

2. Race Conditions Between Interrupts and Main Logic 

Embedded systems rely heavily on interrupts. Incorrect coordination between interrupt handlers and main code can be exploited. Embedded systems rely heavily on interrupts to process asynchronous events such as UART input, sensor readings, or radio traffic. Rust allows this, but interaction between interrupt handlers and main application logic still requires inspection. The compiler cannot reason about timing, preemption, or attacker-controlled input rates. 

static mut AUTH_FLAG: bool = false; 


#[interrupt] 
fn UART_RX() { 
    unsafe { 
        if read_byte() == 0xA5 { 
            AUTH_FLAG = true; 
        } 
    } 
} 

fn privileged_operation() { 
    if unsafe { AUTH_FLAG } { 
        perform_sensitive_action(); 
    } 
} 

3. Cryptographic Misuse Through Nonce Reuse 

Rust cryptography libraries are memory safe and well-reviewed. However, they cannot prevent incorrect usage. Cryptographic security depends on correct protocol design. 

let nonce = [0u8; 12]; 
encrypt_packet(&key, &nonce, data); 

4. Incorrect Assumptions About Debug Port Locking 

Developers often assume hardware is locked after writing a control register. Many devices attempt to disable debug interfaces such as JTAG or SWD after manufacturing. Developers often write firmware to lock these interfaces during boot. 

fn lock_debug_port() { 
    write_reg(DEBUG_LOCK, 0x1); 
} 

5. Trusting Length Fields from Untrusted Inputs 

Rust prevents buffer overflows but cannot prevent flawed trust decisions. Embedded devices parse structured data from external sources such as serial buses, radios, or network protocols. Therefore, Rust ensures memory bounds safety, but it does not enforce trust boundaries. 

let len = frame[1]; 
let payload = &frame[2..2 + len as usize]; 

Why Penetration Testing Remains Essential 

Rust significantly improves safety, but embedded systems remain exposed to: 

• Logic flaws and incorrect trust assumptions 
• Unsafe hardware abstractions 
• Debug and firmware extraction pathways 
• Cryptographic misuse 
• Update and provisioning weaknesses 
• Timing and fault injection attacks 

Professional hardware penetration testing evaluates the full system, not just the source code. It examines firmware, hardware interfaces, communication channels, and operational assumptions under adversarial conditions. 

For senior leadership, the conclusion is clear. Rust lowers risk, but it does not eliminate it. Products written in Rust still require rigorous security assessment before deployment. 

Conclusion 

Rust is one of the most important advances in systems programming in decades. It provides a strong foundation for safer embedded development and reduces the likelihood of catastrophic memory failures. Organizations adopting Rust are making smart technical decisions. 

But secure products are built through design validation, threat modeling, and adversarial testing, not language choice alone. Attackers exploit logic, hardware behavior, and operational gaps, regardless of the language used to write the firmware. Therefore, Rust should be treated as a powerful tool, not a security guarantee.