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.

Published: 2021-01-29 Last update: 2026-06-17 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2021-3345 is rated Moderate Risk (47.6/100): CVSS High severity, with medium exploitation likelihood (EPSS 1.06%). Review affected assets and schedule remediation.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2021-3345

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-15 5.71% 1.06% -4.64%
2 2025-11-21 4.46% 5.71% +1.24%
3 2025-11-18 — 4.46% —

Full EPSS history (20 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2021-3345

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
7.8 3.1 HIGH
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H Click to expand
Attack vector (AV:L)
They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 1.8 5.9 [email protected]
7.2 2.0 HIGH
AV:L/AC:L/Au:N/C:C/I:C/A:C Click to expand
Access vector (AV:L)
Requires local access to the target system.
Access complexity (AC:L)
Exploitation conditions are straightforward and predictable.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:C)
Complete confidentiality impact.
Integrity impact (I:C)
Complete integrity impact.
Availability impact (A:C)
Complete availability impact.
 3.9 10.0 [email protected]

Weakness enumeration for CVE-2021-3345

OS Trackers for CVE-2021-3345

vendor priority summary link
debian unimportant CVE-2021-3345 unimportant priority: Debian including 1 source packages (libgcrypt20), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5. https://security-tracker.debian.org/tracker/CVE-2021-3345
redhat critical — https://access.redhat.com/security/cve/CVE-2021-3345
ubuntu high CVE-2021-3345 high priority: Ubuntu including 2 source packages (libgcrypt11, libgcrypt20), 12 status rows across 6 suites (bionic, focal, groovy, trusty, upstream, xenial): DNE 5, not-affected 5, needs-triage 1, released 1. https://ubuntu.com/security/CVE-2021-3345

Affected software / configurations for CVE-2021-3345

Vendor Product Version Raw CPE
gnupg libgcrypt 1.9.0 cpe:2.3:a:gnupg:libgcrypt:1.9.0:*:*:*:*:*:*:*
oracle communications_billing_and_revenue_management 12.0.0.3.0 cpe:2.3:a:oracle:communications_billing_and_revenue_management:12.0.0.3.0:*:*:*:*:*:*:*

References for CVE-2021-3345

cvelogic Threat Intelligence