CVE-2021-33560

libgcrypt: mishandles ElGamal encryption because it lacks exponent blinding to address a side-channel attack against mpi_powm

Loading…

Severity

Moderate

Red Hat Product Security

7.5

CVSS 3.1

Review impact separately from score.

Published · June 2, 2021

Updated · December 4, 2025

Description

A side-channel attack flaw was found in the way libgcrypt implemented Elgamal encryption. This flaw allows an attacker to decrypt parts of ciphertext encrypted using Elgamal, for example, when using OpenPGP. The highest threat from this vulnerability is to confidentiality.

CVSS score applicability

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.

Mitigation

No mitigation is specified in collected source.

CVSS / CWE

CVSS 3.1 · 7.5
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

CWE-327 · Use of a Broken or Risky Cryptographic Algorithm