CVE-2018-6829

HIGH

Libgcrypt < 1.8.2 - Information Disclosure via ElGamal Ciphertext-Only Attack

Title source: llm
STIX 2.1

Description

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.

References (4)

Core 4
Core References
Exploit, Third Party Advisory x_refsource_misc
https://github.com/weikengchen/attack-on-libgcrypt-elgamal/wiki
Issue Tracking, Third Party Advisory x_refsource_misc
https://lists.gnupg.org/pipermail/gcrypt-devel/2018-February/004394.html

Scores

CVSS v3 7.5
EPSS 0.0181
EPSS Percentile 76.0%
Attack Vector NETWORK
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

Details

CWE
CWE-327
Status published
Products (1)
gnupg/libgcrypt < 1.8.2
Published Feb 07, 2018
Tracked Since Feb 18, 2026