CVE-2023-4387 : Vulnerability Insights and Analysis

This CVE record involves a use-after-free vulnerability in the vmxnet3_rq_alloc_rx_buf function within the vmxnet3 ethernet NIC driver in the Linux Kernel. An attacker can exploit this flaw to potentially crash the system or lead to a kernel information leak issue.

Understanding CVE-2023-4387

This section delves deeper into the details of the CVE-2023-4387 vulnerability, its impact, technical description, affected systems, and mitigation strategies.

What is CVE-2023-4387?

The CVE-2023-4387 vulnerability stems from a use-after-free flaw in the vmxnet3_rq_alloc_rx_buf function in the Linux Kernel's vmxnet3 driver. It poses a risk of system crashes and potential kernel information leaks when exploited by a local attacker.

The Impact of CVE-2023-4387

With a CVSS base score of 7.1 (High severity), the vulnerability's impact includes high confidentiality impact and availability impact. The flaw could allow a malicious actor to execute denial-of-service attacks or extract sensitive kernel information.

Technical Details of CVE-2023-4387

This section covers the technical specifics of the CVE-2023-4387 vulnerability, including its description, affected systems and versions, and exploitation mechanism.

Vulnerability Description

The use-after-free flaw in vmxnet3_rq_alloc_rx_buf could result in a double-free scenario when cleaning up vmxnet3_rq_cleanup_all, leading to system instability and potential kernel information leaks.

Affected Systems and Versions

The vulnerability affects Red Hat Enterprise Linux versions 7, 8, and 9, as well as Fedora. Specifically, certain versions of the 'kernel' and 'kernel-rt' packages in these distributions are impacted.

Exploitation Mechanism

The vulnerability can be exploited by a local attacker to trigger the use-after-free condition, potentially resulting in a system crash or information disclosure.

Mitigation and Prevention

In this section, we explore the steps to mitigate the risks associated with CVE-2023-4387, including immediate actions and long-term security practices.

Immediate Steps to Take

One immediate mitigation technique is to avoid loading the affected 'vmxnet3' module onto the system until a patch is available. This can be achieved by implementing a kernel module blacklist mechanism.

Long-Term Security Practices

To enhance overall system security and resilience, organizations should prioritize regular security updates, vulnerability monitoring, and security awareness training for staff members.

Patching and Updates

It is crucial to promptly apply security patches provided by Linux distributions like Red Hat to address CVE-2023-4387 and other potential vulnerabilities in the system. Regular patch management practices are essential for maintaining a secure infrastructure.