CVE-2021-33560

high

Description

Libgcrypt before 1.8.8 and 1.9.x before 1.9.3 mishandles ElGamal encryption because it lacks exponent blinding to address a side-channel attack against mpi_powm, and the window size is not chosen appropriately. This, for example, affects use of ElGamal in OpenPGP.

References

Advisories
More

https://www.oracle.com/security-alerts/cpuoct2021.html

https://www.oracle.com/security-alerts/cpujul2022.html

https://www.oracle.com/security-alerts/cpujan2022.html

https://www.oracle.com/security-alerts/cpuapr2022.html

https://security.gentoo.org/glsa/202210-13

https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/R7OAPCUGPF3VLA7QAJUQSL255D4ITVTL/

https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/BKKTOIGFW2SGN3DO2UHHVZ7MJSYN4AAB/

https://lists.debian.org/debian-lts-announce/2021/06/msg00021.html

https://github.com/madhunicabala/CVE-Vulnerability-Scanner

https://github.com/IBM/PGP-client-checker-CVE-2021-33560

https://dev.gnupg.org/rCe8b7f10be275bcedb5fc05ed4837a89bfd605c61

https://dev.gnupg.org/T5466

https://dev.gnupg.org/T5328

https://dev.gnupg.org/T5305

Details

Source: Mitre, NVD

Published: 2021-06-08

Updated: 2026-06-17

Risk Information

CVSS v2

Base Score: 5

Vector: CVSS2#AV:N/AC:L/Au:N/C:P/I:N/A:N

Severity: Medium

CVSS v3

Base Score: 7.5

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

Severity: High

EPSS

EPSS: 0.01486