CVE-2023-49083

Publication date 4 December 2023

Last updated 26 August 2025

Ubuntu priority

Cvss 3 Severity Score

Description

cryptography is a package designed to expose cryptographic primitives and recipes to Python developers. Calling `load_pem_pkcs7_certificates` or `load_der_pkcs7_certificates` could lead to a NULL-pointer dereference and segfault. Exploitation of this vulnerability poses a serious risk of Denial of Service (DoS) for any application attempting to deserialize a PKCS7 blob/certificate. The consequences extend to potential disruptions in system availability and stability. This vulnerability has been patched in version 41.0.6.

Read the notes from the security team

Status

Show unmaintained releases

Package	Ubuntu Release	Status
python-cryptography	23.10 mantic	Fixed 38.0.4-4ubuntu0.23.10.1
	23.04 lunar	Fixed 38.0.4-2ubuntu0.1
	22.04 LTS jammy	Fixed 3.4.8-1ubuntu2.1
	20.04 LTS focal	Not affected
	18.04 LTS bionic	Not affected
	16.04 LTS xenial	Not affected
	14.04 LTS trusty	Ignored end of standard support

Notes

mdeslaur

only affects 3.1 and higher

Patch details

For informational purposes only. We recommend not to cherry-pick updates. How can I get the fixes?

Package	Patch details
python-cryptography	Upstream: https://github.com/pyca/cryptography/pull/9926 Upstream: 1e7b4d0 Upstream: f09c261

Severity score breakdown

Parameter	Value
Base score	7.5 · High
Attack vector	Network
Attack complexity	Low
Privileges required	None
User interaction	None
Scope	Unchanged
Confidentiality	None
Integrity impact	None
Availability impact	High
Vector	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

References

Related Ubuntu Security Notices (USN)

USN-6539-1
python-cryptography vulnerabilities
6 December 2023