CVE-2023-49083: cryptography vulnerable to NULL-dereference when loading PKCS7 certificates

Published Nov 28, 2023
·
Updated

Summary

Calling loadpempkcs7certificates or loadderpkcs7certificates could lead to a NULL-pointer dereference and segfault.

PoC Here is a Python code that triggers the issue: python from cryptography.hazmat.primitives.serialization.pkcs7 import loadderpkcs7certificates, loadpempkcs7certificates

pemp7 = b""" -----BEGIN PKCS7----- MAsGCSqGSIb3DQEHAg== -----END PKCS7----- """

derp7 = b"\x30\x0B\x06\x09\x2A\x86\x48\x86\xF7\x0D\x01\x07\x02"

loadpempkcs7certificates(pemp7) loadderpkcs7certificates(derp7)

Impact 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.

Other sources

cryptography is a package designed to expose cryptographic primitives and recipes to Python developers. Calling loadpempkcs7certificates or loadderpkcs7certificates 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.

Ubuntu

Affected Software

9 affected componentsFixes available
pip/cryptography>=3.1<41.0.6
41.0.6
debian/python-cryptography
2.6.1-3+deb10u22.6.1-3+deb10u4
ubuntu/python-cryptography<3.4.8-1ubuntu2.1
3.4.8-1ubuntu2.1
ubuntu/python-cryptography<38.0.4-2ubuntu0.1
38.0.4-2ubuntu0.1
ubuntu/python-cryptography<38.0.4-4ubuntu0.23.10.1
38.0.4-4ubuntu0.23.10.1
cryptography project Cryptography Python>=3.1<41.0.6
Cryptography.io Cryptography Python>=3.1<41.0.6
redhat/python-cryptography<41.0.6
41.0.6
IBM Edge Application Manager<=4.5

Event History

Nov 28, 2023
Advisory Published
via GitHub·08:46 PM
Nov 29, 2023
CVE Published
via MITRE·06:50 PM
Data Sourced
via MITRE·06:50 PM
DescriptionSeverityWeakness
Data Sourced
via NVD·07:15 PM
RemedyDescriptionSeverityWeaknessAffected Software
Dec 20, 2023
Data Sourced
via Red Hat·07:26 AM
DescriptionSeverityAffected Software
Feb 29, 2024
Data Sourced
via Launchpad·12:52 AM
Description
Aug 20, 2025
Data Sourced
via IBM·12:00 AM
DescriptionAffected Software

Parent advisories

This vulnerability appears in the following advisories.

Free Weekly Intel

Don't miss critical vulnerabilities

Join thousands of security professionals who receive our weekly digest of trending CVEs, zero-days, and exploited vulnerabilities.

No spam. Unsubscribe anytime.

Frequently Asked Questions

1

What is the vulnerability ID of this issue?

The vulnerability ID of this issue is CVE-2023-49083.

2

What is the summary of this vulnerability?

Calling `load_pem_pkcs7_certificates` or `load_der_pkcs7_certificates` could lead to a NULL-pointer dereference and segfault.

3

How can this vulnerability be triggered?

This vulnerability can be triggered by calling `load_pem_pkcs7_certificates` or `load_der_pkcs7_certificates`.

4

What is the affected software?

The affected software is cryptography version 3.1 up to and including 41.0.6.

5

Where can I find more information about this vulnerability?

You can find more information about this vulnerability in the following references: [GitHub Advisory GHSA-jfhm-5ghh-2f97](https://github.com/pyca/cryptography/security/advisories/GHSA-jfhm-5ghh-2f97), [GitHub Commit f09c261ca10a31fe41b1262306db7f8f1da0e48a](https://github.com/pyca/cryptography/commit/f09c261ca10a31fe41b1262306db7f8f1da0e48a), [GitHub Advisory GHSA-jfhm-5ghh-2f97](https://github.com/advisories/GHSA-jfhm-5ghh-2f97).

Contact

SecAlerts Pty Ltd.
132 Wickham Terrace
Fortitude Valley,
QLD 4006, Australia
info@secalerts.co
By using SecAlerts services, you agree to our services end-user license agreement. This website is safeguarded by reCAPTCHA and governed by the Google Privacy Policy and Terms of Service. All names, logos, and brands of products are owned by their respective owners, and any usage of these names, logos, and brands for identification purposes only does not imply endorsement. If you possess any content that requires removal, please get in touch with us.
© 2026 SecAlerts Pty Ltd.
ABN: 70 645 966 203, ACN: 645 966 203