Arch Linux Security Advisory ASA-202101-45
=========================================
Severity: Critical
Date    : 2021-01-29
CVE-ID  : CVE-2021-3345
Package : libgcrypt
Type    : arbitrary code execution
Remote  : No
Link    : https://security.archlinux.org/AVG-1505

Summary
======
The package libgcrypt before version 1.9.1-1 is vulnerable to arbitrary
code execution.

Resolution
=========
Upgrade to 1.9.1-1.

# pacman -Syu "libgcrypt>=1.9.1-1"

The problem has been fixed upstream in version 1.9.1.

Workaround
=========
None.

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. Just decrypting some data can overflow a heap buffer
with attacker controlled data, no verification or signature is
validated before the vulnerability occurs. The issue is fixed in
version 1.9.1.

Impact
=====
An attacker is able to execute arbitrary code on the affected host
before a given signature has been verified.

References
=========
https://lists.gnupg.org/pipermail/gnupg-announce/2021q1/000456.html
https://dev.gnupg.org/T5275
https://git.gnupg.org/cgi-bin/gitweb.cgi?p=libgcrypt.git;a=commitdiff;h=512c0c75276949f13b6373b5c04f7065af750b08
https://security.archlinux.org/CVE-2021-3345