RUSTSEC-2019-0019

HMAC-BLAKE2 algorithms compute incorrect results

Reported

August 25, 2019

Issued

October 2, 2020 (last modified: October 19, 2021)

Package

blake2 (crates.io)

Type

Vulnerability

Categories

crypto-failure

Aliases

CVE-2019-16143

Details

https://github.com/RustCrypto/MACs/issues/19

CVSS Score

9.8 CRITICAL

CVSS Details

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

CVSS Vector

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

Patched

>=0.8.1

Description

When used in conjunction with the Hash-based Message Authentication Code (HMAC), the BLAKE2b and BLAKE2s implementations in blake2 crate versions prior to v0.8.1 used an incorrect block size (32-bytes instead of 64-bytes for BLAKE2s, and 64-bytes instead of 128-bytes for BLAKE2b), causing them to miscompute the MacResult.

The v0.8.1 release of the blake2 crate uses the correct block sizes.

Note that this advisory only impacts usage of BLAKE2 with HMAC, and does not impact Digest functionality.