CVE-2021-33560

Published: 08 June 2021

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. (There is also an interoperability problem because the selection of the k integer value does not properly consider the differences between basic ElGamal encryption and generalized ElGamal encryption.) This, for example, affects use of ElGamal in OpenPGP.

Priority

Low

CVSS 3 base score: 7.5

Status

Package Release Status
libgcrypt20
Launchpad, Ubuntu, Debian
Upstream
Released (1.8.7-6)
Ubuntu 21.04 (Hirsute Hippo) Needed

Ubuntu 20.10 (Groovy Gorilla) Ignored
(reached end-of-life)
Ubuntu 20.04 LTS (Focal Fossa) Needed

Ubuntu 18.04 LTS (Bionic Beaver) Needed

Ubuntu 16.04 ESM (Xenial Xerus) Needs triage

Ubuntu 14.04 ESM (Trusty Tahr) Does not exist

Patches:
Upstream: https://git.gnupg.org/cgi-bin/gitweb.cgi?p=libgcrypt.git;a=commit;h=3462280f2e23e16adf3ed5176e0f2413d8861320