CVE-2021-3345

_gcry_md_block_write in cipher/hash-common.c in Libgcrypt before 1.9.1 has a heap-based buffer...

7.8 HighPublic exploit

_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.

Attack profile

How easy it is to exploit

Attack vector: Local
Complexity: Low
Privileges needed: Low
User interaction: None

What an attacker can affect

Confidentiality: High
Integrity: High
Availability: High

Exploit likelihood

1.06%Down 4.3 points since Apr 14, 2021

What each source reports

NVD Score used 7.8

Record: CVE-2021-3345
CVSS 3.1: 7.8 HighCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
CVSS 2.0: 7.2 HighAV:L/AC:L/Au:N/C:C/I:C/A:C
Weakness: CWE-787
Updated: 2026-11-02

CVE List No score

Record: CVE-2021-3345
Updated: 2026-11-02

EUVDEUVD-2021-26676 No score

Record: EUVD-2021-26676
Updated: 2026-11-03

GitHub AdvisoriesGHSA-pf53-rq8f-rwqx 7.8

_gcry_md_block_write in cipher/hash-common.c in Libgcrypt before 1.9.1 has a heap-based buffer...

_gcry_md_block_write in cipher/hash-common.c in Libgcrypt before 1.9.1 has a heap-based buffer overflow when the digest final function sets a large count value.

Record: GHSA-pf53-rq8f-rwqx
CVSS 3.1: 7.8 HighCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Weakness: CWE-787
Updated: 2026-11-02

OSVBELL-CVE-2021-3345 7.8

CVE-2021-3345 does not affect BellSoft software

Record: BELL-CVE-2021-3345
CVSS 3.1: 7.8 HighCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Updated: 2026-11-02

OSV 7.8

Record: CVE-2021-3345
CVSS 3.1: 7.8 HighCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Updated: 2026-11-02

OSVUBUNTU-CVE-2021-3345 7.8

Record: UBUNTU-CVE-2021-3345
CVSS 3.1: 7.8 HighCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Updated: 2026-11-02

OSVopenSUSE-SU-2024:10941-1 No score

libgcrypt-cavs-1.9.4-1.2 on GA media

These are all security issues fixed in the libgcrypt-cavs-1.9.4-1.2 package on the GA media of openSUSE Tumbleweed.

Record: openSUSE-SU-2024:10941-1
Updated: 2026-11-02

Affected products

Affected packages

Affected packages
Package	Affected	Fixed
`libgcrypt` openSUSE:Tumbleweed From an advisory covering 7 CVEs	before 1.9.4-1.2	1.9.4-1.2

Public exploits

Links only. Every CVE stores no exploit code.

Public exploits
Source	Link	Date
PoC in GitHub	MLGRadish/CVE-2021-3345	2021-01-31
PoC in GitHub	SpiralBL0CK/CVE-2021-3345	2024-02-29

History

History
Recorded	Changed	Sources
Nov 6, 2026	affected, facts
Nov 3, 2026	affected
Nov 3, 2026	aliases	EUVD
Nov 2, 2026	first indexed	CVE List, GitHub Advisories, NVD, OSV, PoC in GitHub

Dates are when Every CVE recorded each change. Upstream dates may differ.

In short

CVE-2021-3345 is a high vulnerability (CVSS 7.8) in Gnupg Libgcrypt, published January 29, 2021. Public exploit code exists. EPSS puts the chance of exploitation in the next 30 days at 1.06%, the 64th percentile. No source names a fixed version.

References

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