CVE-2023-5678 : Security Advisory and Response

This CVE record was published by OpenSSL on November 6, 2023, highlighting the issue of generating excessively long X9.42 DH keys or checking these keys, which can lead to significant delays in applications using specific OpenSSL functions.

Understanding CVE-2023-5678

This vulnerability affects the OpenSSL library, impacting applications that utilize certain functions for DH key generation and verification, potentially resulting in a Denial of Service due to prolonged processing times.

What is CVE-2023-5678?

The CVE-2023-5678 vulnerability in OpenSSL involves applications that use DH_generate_key() and DH_check_pub_key() functions to handle X9.42 DH keys. Due to insufficient checks for excessively large DH key parameters, applications may experience prolonged delays, especially when dealing with untrusted sources, posing a risk of Denial of Service attacks.

The Impact of CVE-2023-567

Applications relying on affected OpenSSL functions for DH key operations may encounter extended processing times, potentially leading to service disruptions or slowdowns. The vulnerability could be exploited by attackers providing malicious key or parameter inputs.

Technical Details of CVE-2023-5678

This vulnerability arises from the lack of adequate checks for large DH key parameters in OpenSSL, affecting specific functions and command line applications associated with DH key generation and verification.

Vulnerability Description

OpenSSL functions such as DH_check_pub_key() and DH_generate_key() do not adequately validate excessively large P and Q parameters, making applications vulnerable to performance issues and potential DoS attacks when handling keys from untrusted sources.

Affected Systems and Versions

The versions affected by CVE-2023-5678 include OpenSSL 1.0.2 (prior to version 1.0.2zj), OpenSSL 1.1.1 (before version 1.1.1x), OpenSSL 3.0.0 (up to version 3.0.13), and OpenSSL 3.1.0 (before version 3.1.5).

Exploitation Mechanism

Attackers could exploit this vulnerability by providing excessively long DH key parameters to affected OpenSSL functions, causing delays in key generation and verification processes, potentially disrupting application functionality.

Mitigation and Prevention

To address CVE-2023-5678 and prevent potential security risks associated with the vulnerability, immediate actions and long-term security practices are recommended.

Immediate Steps to Take

Administrators and developers should update OpenSSL to the patched versions (1.0.2zj, 1.1.1x, 3.0.13, and 3.1.5) released by the OpenSSL project to mitigate the risks posed by this vulnerability.

Long-Term Security Practices

Implementing secure coding practices, regular security assessments, and ensuring timely software updates can help maintain a robust security posture and prevent vulnerabilities like CVE-2023-5678 from being exploited.

Patching and Updates

It is crucial for organizations to stay informed about security advisories from OpenSSL and promptly apply patches and updates to address known vulnerabilities, safeguarding their systems and applications from potential threats.

By understanding the impact and technical details of CVE-2023-5678, organizations can take proactive measures to mitigate risks and enhance the security of their systems and applications.