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The CVE-2025-XXXX vulnerability, named “Borrowck Sacrifices,” resides in the improper implementation of the `any_as_u8_slice` function. This safe function is designed to transmute any type into a byte slice. Internally, it uses `std::slice::from_raw_parts` to create a `&
` view of the provided reference. The function calculates the slice length by using <code>size_of::<T>()</code>, which includes any padding bytes within the type's memory layout. However, Rust's memory model does not guarantee that these padding bytes are initialized. The `from_raw_parts` function has a critical safety requirement that all bytes within the created slice must be initialized. By creating a slice that encompasses uninitialized padding bytes, `any_as_u8_slice` violates this invariant, leading to undefined behavior (UB). This UB can potentially expose uninitialized memory contents, which may contain sensitive data from previous allocations, without requiring `unsafe` code from the user. Platform: Rust Version: Pre-patch <h2 style="color: blue;">Vulnerability : Memory Exposure</h2> Severity: Low <h2 style="color: blue;">date: 2024-10-22</h2> <h2 style="color: blue;">Prediction: 2024-11-12</h2> <h2 style="color: blue;">What Undercode Say:</h2> [bash] cargo audit cargo tree
// Code triggering the issue
let my_struct = MyStruct { data: 42, ..uninit }; // Padding uninitialized
let slice: &[bash] = any_as_u8_slice(&my_struct); // UB here
// The vulnerable function
pub fn any_as_u8_slice<T: ?Sized>(data: &T) -> &[bash] {
unsafe {
std::slice::from_raw_parts(
(data as const T) as const u8,
std::mem::size_of_val(data),
)
}
}
How Exploit:
Read uninitialized memory.
Expose sensitive data.
Trigger Undefined Behavior.
Protection from this CVE
Update Rust compiler.
Avoid vulnerable `any_as_u8_slice`.
Use initialized types.
Audit dependencies.
Impact:
Information Disclosure.
Undefined Behavior.
Low Severity.
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Sources:
Reported By: github.com
Extra Source Hub:
Undercode
