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The `reciprocal_mg10` function in the `ruint` crate is publicly marked as safe, implying it cannot trigger undefined behavior (UB). However, its safety relies on input validation performed by `debug_assert!` macros. The `debug_assert!` macro is only active in debug builds; it is completely removed by the compiler when building in release mode (--release). Consequently, in release builds, these critical bounds checks are absent. An attacker can provide carefully crafted input that would be rejected in a debug build but passes silently in release. This invalid input leads to an out-of-bounds array access within the function’s logic, violating Rust’s memory safety guarantees and causing undefined behavior, which can manifest as memory corruption, application crashes, or potentially exploitable conditions.
Platform: ruint crate
Version: Affected versions
Vulnerability: Memory Corruption
Severity: Moderate
Date: 2024-12-26
Prediction: Patch by 2025-01-16
What Undercode Say:
cargo audit cargo update -p ruint
// Example vulnerable code pattern
pub fn reciprocal_mg10(input: usize) -> u32 {
let table = [1u32, 2, 3, 4, 5];
debug_assert!(input < table.len()); // Removed in --release
table[bash] // OOB access possible
}
How Exploit:
Craft input > array length, compile target with `–release` flag, trigger out-of-bounds read/write.
Protection from this CVE
Update `ruint` to patched version. Replace `debug_assert!` with `assert!` or proper `if` check returning Result/Option.
Impact:
Memory corruption, denial-of-service, potential arbitrary code execution.
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Sources:
Reported By: github.com
Extra Source Hub:
Undercode
