RUSTSEC-2021-0048

StackVec::extend can write out of bounds when size_hint is incorrect

Reported

February 19, 2021

Issued

March 30, 2021 (last modified: October 19, 2021)

Package

stackvector (crates.io)

Type

Vulnerability

Categories

memory-corruption

Aliases

CVE-2021-29939

Details

https://github.com/Alexhuszagh/rust-stackvector/issues/2

CVSS Score

7.3 HIGH

CVSS Details

Attack vector: Network
Attack complexity: Low
Privileges required: None
User interaction: None
Scope: Unchanged
Confidentiality: Low
Integrity: Low
Availability: Low

CVSS Vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L

Patched

>=1.0.9

Description

StackVec::extend used the lower and upper bounds from an Iterator's size_hint to determine how many items to push into the stack based vector.

If the size_hint implementation returned a lower bound that was larger than the upper bound, StackVec would write out of bounds and overwrite memory on the stack. As mentioned by the size_hint documentation, size_hint is mainly for optimization and incorrect implementations should not lead to memory safety issues.