CVE-2023-4387 in Linux
Summary
by MITRE • 08/16/2023
A use-after-free flaw was found in vmxnet3_rq_alloc_rx_buf in drivers/net/vmxnet3/vmxnet3_drv.c in VMware's vmxnet3 ethernet NIC driver in the Linux Kernel. This issue could allow a local attacker to crash the system due to a double-free while cleaning up vmxnet3_rq_cleanup_all, which could also lead to a kernel information leak problem.
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Analysis
by VulDB Data Team • 07/26/2025
The vulnerability CVE-2023-4387 represents a critical use-after-free flaw within the vmxnet3 ethernet NIC driver component of the Linux kernel ecosystem. This issue specifically manifests in the vmxnet3_rq_alloc_rx_buf function located within the drivers/net/vmxnet3/vmxnet3_drv.c file, where improper memory management leads to a dangerous state that can be exploited by local attackers. The vulnerability stems from a double-free condition that occurs during the vmxnet3_rq_cleanup_all cleanup routine, creating an exploitable scenario that can result in system instability and potential privilege escalation.
The technical exploitation of this vulnerability involves a local attacker leveraging the improper memory handling to trigger a use-after-free condition that ultimately results in a double-free operation. When the vmxnet3 driver attempts to clean up resources during vmxnet3_rq_cleanup_all, the memory allocation and deallocation sequence becomes corrupted, allowing an attacker to manipulate memory pointers and potentially execute arbitrary code within kernel space. This flaw directly maps to CWE-416, which specifically addresses use-after-free vulnerabilities, and represents a classic example of improper memory management that can lead to privilege escalation and system compromise. The vulnerability is particularly concerning because it operates at the kernel level, where successful exploitation can provide attackers with elevated privileges and complete system control.
The operational impact of CVE-2023-4387 extends beyond simple system crashes to include potential information disclosure and privilege escalation capabilities. A successful exploitation could allow a local attacker to gain kernel-level privileges, enabling them to access sensitive system information, modify kernel memory, and potentially establish persistent backdoors. The double-free condition creates a memory corruption state that can be leveraged through various attack vectors, including process manipulation and kernel memory spraying techniques. This vulnerability affects systems running Linux kernels with the vmxnet3 driver implementation, which is commonly found in virtualized environments where VMware virtual machines utilize this network interface driver. The attack surface is particularly large given the widespread adoption of VMware virtualization solutions across enterprise environments, making this vulnerability a significant concern for organizations maintaining virtualized infrastructures.
Mitigation strategies for CVE-2023-4387 should prioritize immediate patching of affected systems through kernel updates that address the memory management issues within the vmxnet3 driver. Organizations should implement network segmentation and access controls to limit local user privileges and reduce the attack surface available to potential exploiters. The remediation process should include comprehensive system auditing to identify all affected virtual machines and kernel versions, followed by systematic patch deployment across all environments. Security teams should also implement monitoring solutions to detect anomalous memory allocation patterns and potential exploitation attempts. Additionally, organizations should consider disabling unnecessary virtual network interfaces and implementing strict virtual machine access controls to minimize the risk of local privilege escalation. The vulnerability's classification under ATT&CK technique T1068, which covers local privilege escalation, indicates that exploitation could lead to complete system compromise, making immediate remediation essential for maintaining operational security.