How severe is CVE-2021-3345?

CVE-2021-3345 has a CVSS 3.x base score of 7.8, rated high severity. It is exploitable over local access with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2021-3345 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (61st percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-3345?

CVE-2021-3345 primarily affects Gnupg Libgcrypt. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2021-3345?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

When was CVE-2021-3345 published?

CVE-2021-3345 was published on 2021-01-29 and last updated on 2026-06-17.

CVE-2021-3345

CVE-2021-3345 is a high-severity vulnerability in Gnupg Libgcrypt with a CVSS 3.x base score of 7.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-787.

Key facts

Severity: High (CVSS 3.x base score 7.8)
CVSS v2: 7.2
EPSS exploit prediction: 1% (61st percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-787
Affected product: Gnupg Libgcrypt
Published: 2021-01-29
Last modified: 2026-06-17

Description

_gcry_md_block_write in cipher/hash-common.c in Libgcrypt version 1.9.0 has a heap-based buffer overflow when the digest final function sets a large count value. It is recommended to upgrade to 1.9.1 or later.

Frequently asked questions

What is CVE-2021-3345?: _gcry_md_block_write in cipher/hash-common.c in Libgcrypt version 1.9.0 has a heap-based buffer overflow when the digest final function sets a large count value. It is recommended to upgrade to 1.9.1 or later.
How severe is CVE-2021-3345?: CVE-2021-3345 has a CVSS 3.x base score of 7.8, rated high severity. It is exploitable over local access with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2021-3345 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (61st percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-3345?: CVE-2021-3345 primarily affects Gnupg Libgcrypt. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2021-3345?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2021-3345 published?: CVE-2021-3345 was published on 2021-01-29 and last updated on 2026-06-17.

References

Affected products (2)

cpe:2.3:a:gnupg:libgcrypt:1.9.0:*:*:*:*:*:*:*
cpe:2.3:a:oracle:communications_billing_and_revenue_management:12.0.0.3.0:*:*:*:*:*:*:*

More vulnerabilities in Gnupg Libgcrypt

CVE-2021-33560 — High (CVSS 7.5): Libgcrypt before 1.8.8 and 1.9.x before 1.9.3 mishandles ElGamal encryption because it lacks exponent blinding to…
CVE-2018-6829 — High (CVSS 7.5): cipher/elgamal.c in Libgcrypt through 1.8.2, when used to encrypt messages directly, improperly encodes plaintexts,…
CVE-2017-0379 — High (CVSS 7.5): Libgcrypt before 1.8.1 does not properly consider Curve25519 side-channel attacks, which makes it easier for attackers…
CVE-2026-41989 — Medium (CVSS 6.7): Libgcrypt before 1.12.2 sometimes allows a heap-based buffer overflow and denial of service via crafted ECDH ciphertext…
CVE-2017-7526 — Medium (CVSS 6.1): libgcrypt before version 1.7.8 is vulnerable to a cache side-channel attack resulting into a complete break of RSA-1024…
CVE-2021-40528 — Medium (CVSS 5.9): The ElGamal implementation in Libgcrypt before 1.9.4 allows plaintext recovery because, during interaction between two…

All CVEs affecting Gnupg Libgcrypt →

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