CVE-2021-3345

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.

Fixed in Linux distributions

Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.

openSUSE

Security tracker ↗

Release	Package	Fixed in	Advisory
openSUSE Tumbleweed	libgcrypt	1.9.4-1.2	openSUSE-SU-2024:10941-1

Public exploits

Exploit or proof-of-concept code for this vulnerability is publicly available, which lowers the bar for attackers. Treat it as a reason to patch sooner.

Third-party code, not reviewed by us. Public PoCs are sometimes fake or contain malware. Read the code first and run it only in an isolated lab, against systems you are authorised to test.

GitHub 2 repositories

MLGRadish/CVE-2021-3345 ★ 9 · Jan 31, 2021

POC exploit of CVE-2021-3345, a vulnerability in libgcrypt version 1.9.0
SpiralBL0CK/CVE-2021-3345 ★ 3 · Feb 29, 2024

Actual working exploit for CVE-2021-3345

Sources: PoC-in-GitHub, Metasploit Framework, Exploit-DB — updated daily. Only links are listed; no exploit code is hosted here.

Advisories 1

openSUSE-SU-2024:10941-1 libgcrypt-cavs-1.9.4-1.2 on GA media SUSE / openSUSE Security Updates · Feb 4, 2026

_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 set…