A python-cryptography security update has been released for Arch Linux.

ASA-202102-36: python-cryptography: incorrect calculation

Arch Linux Security Advisory ASA-202102-36
=========================================
Severity: Medium
Date : 2021-02-27
CVE-ID : CVE-2020-36242
Package : python-cryptography
Type : incorrect calculation
Remote : No
Link :   https://security.archlinux.org/AVG-1541

Summary
======
The package python-cryptography before version 3.4-1 is vulnerable to
incorrect calculation.

Resolution
=========
Upgrade to 3.4-1.

# pacman -Syu "python-cryptography>=3.4-1"

The problem has been fixed upstream in version 3.4.

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

Description
==========
In python-cryptography before version 3.3.2, certain sequences of
update calls to symmetrically encrypt multiple gigabytes of data could
result in an integer overflow, leading to mishandling of buffers.

Impact
=====
Unintentional use of the API could lead to buffer mishandling, causing
application crashes or incorrectly encrypted data.

References
=========
  https://github.com/pyca/cryptography/security/advisories/GHSA-rhm9-p9w5-fwm7
  https://github.com/pyca/cryptography/issues/5615
  https://github.com/pyca/cryptography/pull/5747
  https://github.com/pyca/cryptography/commit/82b6ce28389f0a317bc55ba2091a74b346db7cae
  https://security.archlinux.org/CVE-2020-36242