CVE-2023-49083: Cryptographic Vulnerability in cryptography Package

In the intricate web of digital security, a recent revelation has sent ripples through the Python developer community. The widely used Python package ‘cryptography’, renowned for its cryptographic recipes and primitives, has encountered a formidable security vulnerability. This package, boasting over 5,900 stars on GitHub and critical dependency in over 579,000 repositories, stands as a cornerstone in the Python programming world.


At the heart of this issue lies CVE-2023-49083, a vulnerability with a formidable Common Vulnerability Scoring System (CVSS) score of 9.1, as calculated by GitHub. This flaw, a NULL-dereference when loading PKCS7 certificates, presents a significant threat. The functions load_pem_pkcs7_certificates and load_der_pkcs7_certificates are prone to a NULL-pointer dereference, potentially leading to a segmentation fault (segfault).

The exploitation of this vulnerability poses a severe risk of Denial of Service (DoS) for any application attempting to deserialize a PKCS7 blob/certificate. This flaw doesn’t just threaten data security; it jeopardizes the availability and stability of systems relying on the cryptography package. In a digital ecosystem where uptime is paramount, this vulnerability could lead to catastrophic disruptions.

This flaw affects versions of the cryptography package starting from 3.1. However, the vigilant efforts of the Python community have led to a patch in version 41.0.6. This rapid response underscores the community’s commitment to security and the proactive stance against digital threats.

The discovery of CVE-2023-49083 can be credited to the astute observations of security researcher pkuzco. Not only did pkuzco identify this critical flaw, but they also published a proof-of-concept, enlightening the community about the potential risks and encouraging prompt remediation.

To mitigate the threat, it is imperative for developers to promptly update their applications to the latest version. Additionally, implementing input validation mechanisms can further enhance security by preventing the processing of potentially malicious PKCS7 data.