Libgcrypt
CVE-2021-33560
HIGH
Vulnerability Assessment
| Weakness |
CWE
ASVS 5.0
V6 - Authentication Timing-safe comparisons
|
| Impact | CVSS score of 7.5 (HIGH). Attack characteristics: network attack vector, low complexity, no privileges required, no user interaction not required. |
| Exploit ScenarioDerived | This vulnerability can be exploited remotely over the network. Successful exploitation could compromise the high-severity affected system. |
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Alert meAnalysisAI
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. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity.
RemediationAI
A vendor patch is available. Apply the latest security update as soon as possible. Apply vendor patches when available. Implement network segmentation and monitoring as interim mitigations.
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Technical ContextAI · show details
This vulnerability is classified under CWE-203. 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. Affected products include: Gnupg Libgcrypt, Debian Debian Linux, Fedoraproject Fedora, Oracle Communications Cloud Native Core Binding Support Function, Oracle Communications Cloud Native Core Network Function Cloud Native Environment. Version information: before 1.8.8.
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Severity by source
AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
Primary rating from NVD · only source for this CVE.
CVSS VectorNVD
DescriptionNVD
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.
Threat Intelligence Overview
How this decision was reached
The engine reads each signal below and applies a fixed list of rules from top to bottom. The first rule that matches sets the recommended action – like a statement, every line is shown.
What every action level means
SSVC AssessmentENISA
Priority Score
Attack Technique
Information disclosure occurs when an application unintentionally exposes sensitive data that aids attackers in reconnaissance or directly compromises security.
Affected Products (CPE)NVD
cipher/elgamal.c in Libgcrypt through 1.8.2, when used to encrypt messages directly, improperly encodes plaintexts, whic
The ElGamal implementation in Libgcrypt before 1.9.4 allows plaintext recovery because, during interaction between two c
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
Heap-based buffer overflow in Libgcrypt before 1.12.2 allows local attackers to trigger denial of service and corrupt me
_gcry_md_block_write in cipher/hash-common.c in Libgcrypt version 1.9.0 has a heap-based buffer overflow when the digest
Libgcrypt before 1.8.1 does not properly consider Curve25519 side-channel attacks, which makes it easier for attackers t
In Libgcrypt 1.8.4, the C implementation of AES is vulnerable to a flush-and-reload side-channel attack because physical
In Libgcrypt before 1.7.7, an attacker who learns the EdDSA session key (from side-channel observation during the signin
The mixing functions in the random number generator in Libgcrypt before 1.5.6, 1.6.x before 1.6.6, and 1.7.x before 1.7.
Libgcrypt before version 1.12.2 contains a bounds-check vulnerability in Dilithium signing operations where writes to a
Libgcrypt before 1.5.4, as used in GnuPG and other products, does not properly perform ciphertext normalization and ciph
Libgcrypt before 1.6.5 does not properly perform elliptic-point curve multiplication during decryption, which makes it e
NVD
CVE.org
EPSS
GitHub PoC
Exploit-DB