Security of Rust Applications: Top 10 Vulnerabilities and Their Prevention

Security of Rust applications: top 10 vulnerabilities and practical protection methods

The Rust language is deservedly considered one of the safest systems programming languages. Its ownership system, borrowing mechanisms, and lifetimes at compile time prevent entire classes of vulnerabilities related to memory management. However, as practice shows, Rust security is not absolute. Design errors, incorrect use of unsafe code, and logical bugs can lead to serious vulnerabilities.

In this article, we will analyze the top 10 vulnerabilities of Rust applications that every developer should know. You will learn not only the reasons for their occurrence but also get specific code examples and protection methods.

1. Incorrect use of unsafe code

unsafe is the most powerful but also the most dangerous tool in Rust. It disables compiler checks, allowing dereferencing raw pointers, calling unsafe functions, and accessing mutable static variables. According to research, more than 70% of all critical vulnerabilities in Rust projects are related to unsafe code.

Vulnerability example: dereferencing a null pointer in an unsafe block.

fn dangerous() {    let ptr: *const i32 = std::ptr::null();    unsafe {        println!("{}", *ptr); // Undefined Behavior!    }}

How to protect yourself:

• Minimize the use of unsafe. Isolate it into small, thoroughly tested functions.
• Always check pointers for null before dereferencing.
• Use tools like Miri to detect undefined behavior.

2. Data Races in multithreaded code

Rust guarantees the absence of data races in safe code thanks to its type system. However, when using unsafe or incorrect synchronization, races are still possible. Races when working with global mutable statics are especially dangerous.

Vulnerability example: accessing a static mutable variable without synchronization.

static mut COUNTER: u32 = 0;

fn increment() {    unsafe {        COUNTER += 1; // Data race in a multithreaded environment    }}

How to protect yourself:

• Use Mutex, RwLock, or atomic types (AtomicU32).
• Avoid global mutable states. Prefer passing ownership through channels (mpsc).
• Apply Send and Sync traits deliberately.

3. Buffer Overflow in Rust

In safe Rust, buffer overflow is practically impossible — the compiler checks array bounds. But when working with low-level structures in unsafe or when using FFI (Foreign Function Interface), overflow becomes a real threat.

Vulnerability example: copying data beyond the buffer via FFI.

use std::ffi::CString;

extern "C" {    fn unsafe_copy(dest: *mut u8, src: *const u8, len: usize);}

fn copy_vulnerable(data: &[u8]) {    let dest = CString::new("").unwrap();    unsafe {        unsafe_copy(dest.into_raw(), data.as_ptr(), data.len()); // Overflow!    }}

How to protect yourself:

• Always check the buffer length on the Rust side before calling C functions.
• Use wrapper crates for C libraries that guarantee safety.
• Apply sanitizers (AddressSanitizer) during testing.

4. Memory Leaks

Although Rust does not have a garbage collector, its ownership system