CVE-2023-5633 : Security Advisory and Response

This CVE, assigned by Red Hat, involves a kernel vulnerability in the vmwgfx module that can lead to a use-after-free issue in surface handling, potentially allowing a local, unprivileged user to escalate their privileges.

Understanding CVE-2023-5633

This section delves into the specifics of CVE-2023-5633, outlining the vulnerability, its impact, technical details, affected systems, and mitigation strategies.

What is CVE-2023-5633?

The vulnerability stems from changes made to reference counts in previous fixes, exposing a flaw in memory object handling when used to store a surface. It can be exploited by a local, unprivileged user within a VMware guest with 3D acceleration enabled.

The Impact of CVE-2023-5633

The impact of this vulnerability is rated as "High" by Red Hat, with significant implications for confidentiality, integrity, and availability of affected systems. Exploitation by malicious actors could lead to privilege escalation.

Technical Details of CVE-2023-5633

This section provides more in-depth technical insights into the vulnerability, including a description, affected systems and versions, and the exploitation mechanism.

Vulnerability Description

The use-after-free flaw in the vmwgfx module arises from changes in reference counts, potentially allowing unauthorized users to manipulate memory objects and escalate privileges.

Affected Systems and Versions

Kernel: Version 6.6-rc6 (unaffected)
Red Hat Enterprise Linux 8: Versions 4.18.0-513.11.1.rt7.313.el8_9, 4.18.0-513.11.1.el8_9
Red Hat Enterprise Linux 6 & 7: Not affected
Red Hat Enterprise Linux 9: Versions 9 (kernel and kernel-rt affected)
Fedora: All versions of the kernel affected

Exploitation Mechanism

The vulnerability can be exploited by a local, unprivileged user within a VMware guest environment with 3D acceleration enabled to manipulate memory objects containing surfaces and potentially elevate their privileges.

Mitigation and Prevention

Understanding how to mitigate and prevent the CVE-2023-5633 vulnerability is crucial to safeguarding systems from potential exploitation.

Immediate Steps to Take

To mitigate this vulnerability, consider turning off 3D acceleration in VMware or preventing the affected

vmwgfx

kernel module from loading. Refer to Red Hat's documentation for detailed instructions on blacklisting kernel modules.

Long-Term Security Practices

Implementing best cybersecurity practices, such as regular security updates, secure configuration management, and access control, can help prevent similar vulnerabilities from being exploited in the future.

Patching and Updates

Stay informed about security advisories and updates from Red Hat to apply patches promptly and ensure that systems are protected against known vulnerabilities.

By understanding the details and impact of CVE-2023-5633 and taking proactive security measures, organizations can enhance their cybersecurity posture and protect their systems from potential threats.