RUSTSEC-2020-0089

nanorand 0.5.0 - RNGs failed to generate properly for non-64-bit numbers

Reported

December 9, 2020

Issued

December 9, 2020 (last modified: January 4, 2021)

Package

nanorand (crates.io)

Type

Vulnerability

Categories

crypto-failure

Keywords

#rng

Aliases

CVE-2020-35926

Details

https://twitter.com/aspenluxxxy/status/1336684692284772352

CVSS Score

5.1 MEDIUM

CVSS Details

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

CVSS Vector

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

Patched

>=0.5.1

Description

In versions of nanorand prior to 0.5.1, RandomGen implementations for standard unsigned integers could fail to properly generate numbers, due to using bit-shifting to truncate a 64-bit number, rather than just an as conversion.

This often manifested as RNGs returning nothing but 0, including the cryptographically secure ChaCha random number generator..