
CVE-2021-40528 – libgcrypt: ElGamal implementation allows plaintext recovery
https://notcve.org/view.php?id=CVE-2021-40528
06 Sep 2021 — The ElGamal implementation in Libgcrypt before 1.9.4 allows plaintext recovery because, during interaction between two cryptographic libraries, a certain dangerous combination of the prime defined by the receiver's public key, the generator defined by the receiver's public key, and the sender's ephemeral exponents can lead to a cross-configuration attack against OpenPGP. Una implementación de ElGamal en Libgcrypt versiones anteriores a 1.9.4, permite una recuperación de texto plano porque, durante la intera... • https://eprint.iacr.org/2021/923 • CWE-327: Use of a Broken or Risky Cryptographic Algorithm •

CVE-2021-33560 – libgcrypt: mishandles ElGamal encryption because it lacks exponent blinding to address a side-channel attack against mpi_powm
https://notcve.org/view.php?id=CVE-2021-33560
08 Jun 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. This, for example, affects use of ElGamal in OpenPGP. Libgcrypt versiones anteriores a 1.8.8 y versiones 1.9.x anteriores a 1.9.3, maneja inapropiadamente el cifrado de ElGamal porque carece de cegado de exponentes para hacer frente a un ataque de canal lateral contra la función mpi_powm, y el tamaño... • https://github.com/IBM/PGP-client-checker-CVE-2021-33560 • CWE-203: Observable Discrepancy CWE-327: Use of a Broken or Risky Cryptographic Algorithm •

CVE-2018-0495 – ROHNP: Key Extraction Side Channel in Multiple Crypto Libraries
https://notcve.org/view.php?id=CVE-2018-0495
13 Jun 2018 — Libgcrypt before 1.7.10 and 1.8.x before 1.8.3 allows a memory-cache side-channel attack on ECDSA signatures that can be mitigated through the use of blinding during the signing process in the _gcry_ecc_ecdsa_sign function in cipher/ecc-ecdsa.c, aka the Return Of the Hidden Number Problem or ROHNP. To discover an ECDSA key, the attacker needs access to either the local machine or a different virtual machine on the same physical host. Libgcrypt en versiones anteriores a la 1.7.10 y versiones 1.8.x anteriores... • http://www.securitytracker.com/id/1041144 • CWE-200: Exposure of Sensitive Information to an Unauthorized Actor CWE-203: Observable Discrepancy •

CVE-2018-6829
https://notcve.org/view.php?id=CVE-2018-6829
07 Feb 2018 — cipher/elgamal.c in Libgcrypt through 1.8.2, when used to encrypt messages directly, improperly encodes plaintexts, which allows attackers to obtain sensitive information by reading ciphertext data (i.e., it does not have semantic security in face of a ciphertext-only attack). The Decisional Diffie-Hellman (DDH) assumption does not hold for Libgcrypt's ElGamal implementation. cipher/elgamal.c en Libgcrypt hasta la versión 1.8.2, al emplearse para cifrar mensajes directamente, cifra los textos planos indebid... • https://github.com/weikengchen/attack-on-libgcrypt-elgamal • CWE-327: Use of a Broken or Risky Cryptographic Algorithm •

CVE-2017-0379 – Slackware Security Advisory - libgcrypt Updates
https://notcve.org/view.php?id=CVE-2017-0379
29 Aug 2017 — Libgcrypt before 1.8.1 does not properly consider Curve25519 side-channel attacks, which makes it easier for attackers to discover a secret key, related to cipher/ecc.c and mpi/ec.c. Libgcrypt en versiones anteriores a la 1.8.1 no considera correctamente ataques de canal lateral Curve25519, lo que facilita que los atacantes descubran una clave secreta relacionada con cipher/ecc.c y mpi/ec.c. Daniel Genkin, Luke Valenta, and Yuval Yarom discovered that Libgcrypt was susceptible to an attack via side channels... • http://www.oracle.com/technetwork/security-advisory/cpujul2018-4258247.html • CWE-200: Exposure of Sensitive Information to an Unauthorized Actor •