CVE-2023-23931 Explained : Impact and Mitigation

This is a detailed description of CVE-2023-23931, providing insights into the vulnerability, its impact, technical details, and mitigation strategies.

Understanding CVE-2023-23931

CVE-2023-23931 relates to a vulnerability in the

Cipher.update_into

function within the

cryptography

package. This vulnerability can lead to memory corruption, potentially affecting systems that use this functionality.

What is CVE-2023-23931?

The vulnerability in

Cipher.update_into

allows Python objects with immutable buffers to be mutated, violating basic Python rules and resulting in corrupted data output. This issue has been present since the introduction of the

update_into

function in cryptography version 1.8.

The Impact of CVE-2023-23931

The impact of this vulnerability is rated as medium severity. While the confidentiality impact is none, the integrity impact is low, and the availability impact is also low. The attack complexity is high, with the attack vector being network-based.

Technical Details of CVE-2023-23931

This section dives into the technical aspects of the vulnerability, outlining the description, affected systems, versions, and exploitation mechanism.

Vulnerability Description

The vulnerability arises from the improper handling of Python objects implementing the buffer protocol, specifically immutable buffers in the context of

Cipher.update_into

. This allows for the mutation of immutable objects like

bytes

, leading to corrupted output.

Affected Systems and Versions

The

pyca cryptography

package versions ranging from

>=1.8

to

<39.0.1

are impacted by this vulnerability, highlighting the importance of addressing this issue for systems within this version range.

Exploitation Mechanism

The exploitation of this vulnerability can occur through leveraging the

update_into

function in a way that allows for the mutation of immutable buffers, leading to memory corruption and potentially enabling malicious actors to compromise system integrity.

Mitigation and Prevention

To address CVE-2023-23931, immediate steps should be taken to mitigate the risk posed by this vulnerability and prevent potential exploitation.

Immediate Steps to Take

Developers and users are advised to update to a non-vulnerable version of the

cryptography

package, ensuring that systems are protected against memory corruption and data integrity issues stemming from this vulnerability.

Long-Term Security Practices

Implementing secure coding practices, regularly updating software dependencies, and conducting thorough code reviews can bolster overall system security and reduce the likelihood of similar vulnerabilities surfacing in the future.

Patching and Updates

Staying informed about security advisories and promptly applying patches released by the

pyca cryptography

package maintainers can help safeguard systems against known vulnerabilities, including those like CVE-2023-23931 that pose potential risks to data integrity and system stability.