CVE Vulnerabilities

CVE-2017-18021

Use of Cryptographically Weak Pseudo-Random Number Generator (PRNG)

Published: Jan 05, 2018 | Modified: Jan 18, 2018
CVSS 3.x
9.8
CRITICAL
Source:
NVD
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
CVSS 2.x
5 MEDIUM
AV:N/AC:L/Au:N/C:P/I:N/A:N
RedHat/V2
RedHat/V3
Ubuntu
MEDIUM

It was discovered that QtPass before 1.2.1, when using the built-in password generator, generates possibly predictable and enumerable passwords. This only applies to the QtPass GUI.

Weakness

The product uses a Pseudo-Random Number Generator (PRNG) in a security context, but the PRNG’s algorithm is not cryptographically strong.

Affected Software

Name Vendor Start Version End Version
Qtpass Qtpass * 1.2.1 (excluding)
Qtpass Ubuntu artful *
Qtpass Ubuntu esm-apps/xenial *
Qtpass Ubuntu upstream *
Qtpass Ubuntu xenial *
Qtpass Ubuntu zesty *

Extended Description

When a non-cryptographic PRNG is used in a cryptographic context, it can expose the cryptography to certain types of attacks. Often a pseudo-random number generator (PRNG) is not designed for cryptography. Sometimes a mediocre source of randomness is sufficient or preferable for algorithms that use random numbers. Weak generators generally take less processing power and/or do not use the precious, finite, entropy sources on a system. While such PRNGs might have very useful features, these same features could be used to break the cryptography.

Potential Mitigations

References