Arch Linux alert ASA-202102-36 (python-cryptography)

From:
             
 
Morten Linderud via arch-security <arch-security@lists.archlinux.org>
To:
             
 
arch-security@archlinux.org
Subject:
             
 
[ASA-202102-36] python-cryptography: incorrect calculation
Date:
             
 
Mon, 01 Mar 2021 23:23:36 +0100
Message-ID:
             
 
<20210301222336.fzk6k6duvwegh3ch@anathema>
Cc:
             
 
Morten Linderud <foxboron@archlinux.org>
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/...
https://github.com/pyca/cryptography/issues/5615
https://github.com/pyca/cryptography/pull/5747
https://github.com/pyca/cryptography/commit/82b6ce28389f0...
https://security.archlinux.org/CVE-2020-36242