CVE-2023-5981 Explained : Impact and Mitigation

A vulnerability has been identified in GnuTLS that affects the RSA-PSK authentication process, potentially leading to timing side-channel attacks. This CVE was published by Red Hat and carries a moderate severity rating.

Understanding CVE-2023-5981

This section will delve into the details of CVE-2023-5981, including what the vulnerability entails, its impact, technical details, affected systems, and mitigation strategies.

What is CVE-2023-5981?

The vulnerability in CVE-2023-5981 involves response time discrepancies when handling malformed ciphertexts in the RSA-PSK ClientKeyExchange within GnuTLS. Specifically, the response times differ between malformed ciphertexts and those with correct PKCS#1 v1.5 padding.

The Impact of CVE-2023-5981

The impact of this vulnerability lies in the potential for attackers to exploit the timing side-channel to gain insights into the cryptographic operations of affected systems. This could lead to confidentiality breaches in environments where RSA-PSK authentication is utilized.

Technical Details of CVE-2023-5981

This section outlines the technical aspects of the vulnerability, including a description of the issue, affected systems and versions, and the exploitation mechanism.

Vulnerability Description

The vulnerability stems from the observed differences in response times when processing malformed ciphertexts in the RSA-PSK ClientKeyExchange protocol.

Affected Systems and Versions

GnuTLS version 3.8.2 is unaffected.
Red Hat Enterprise Linux 8 versions prior to 3.6.16-8.el8_9 are affected.
Red Hat Enterprise Linux 8.6 Extended Update Support versions prior to 3.6.16-5.el8_6.2 are affected.
Red Hat Enterprise Linux 6 and 7 have an unknown status regarding the vulnerability.
Fedora 37 and 38 are affected.
Fedora with mingw-gnutls has an unknown vulnerability status.

Exploitation Mechanism

The vulnerability can be exploited through analyzing the timing discrepancies in the response times of malformed and correctly padded ciphertexts, potentially revealing sensitive information.

Mitigation and Prevention

In light of CVE-2023-5981, it is crucial to implement appropriate mitigation measures to secure affected systems and prevent potential exploitation.

Immediate Steps to Take

Upgrade GnuTLS to version 3.8.2 or later to address the identified vulnerability.

Long-Term Security Practices

Regularly monitor security advisories from Red Hat and GnuTLS to stay informed about patches and updates.
Implement secure coding practices and cryptography best practices to reduce the risk of similar vulnerabilities in the future.

Patching and Updates

Stay updated with security bulletins and advisories from vendors to promptly apply patches for CVE-2023-5981.
Consider implementing automated patch management solutions to streamline the patching process and enhance overall security posture.