CVE-2023-1670 in Linux
Summary
by MITRE • 03/31/2023
A flaw use after free in the Linux kernel Xircom 16-bit PCMCIA (PC-card) Ethernet driver was found.A local user could use this flaw to crash the system or potentially escalate their privileges on the system.
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Analysis
by VulDB Data Team • 08/12/2025
The vulnerability identified as CVE-2023-1670 represents a critical use-after-free flaw within the Linux kernel's Xircom 16-bit PCMCIA Ethernet driver implementation. This type of vulnerability occurs when a program continues to reference memory after it has been freed, creating potential exploitation opportunities for malicious actors. The flaw specifically affects the legacy PCMCIA card driver functionality that handles 16-bit Ethernet network interface cards, which while considered outdated technology still maintains relevance in embedded systems and specialized industrial applications where legacy hardware support is required.
The technical nature of this vulnerability stems from improper memory management within the kernel's device driver subsystem, where the Xircom PCMCIA driver fails to properly handle memory deallocation and subsequent access patterns. When the driver processes certain network packet operations or device state transitions, it may free memory structures while still maintaining references to them, allowing for potential arbitrary code execution or system crashes. This memory management error aligns with CWE-416, which specifically addresses use-after-free vulnerabilities where program memory is accessed after it has been freed. The vulnerability exists at the kernel level, making it particularly dangerous as it operates within the most privileged execution context of the operating system.
From an operational impact perspective, this vulnerability creates significant risk for systems that continue to rely on legacy PCMCIA Ethernet hardware or those that have not properly deprecated support for such devices. A local attacker with minimal privileges could potentially exploit this flaw to either cause a denial of service through system crashes or escalate their privileges to kernel-level execution. The privilege escalation capability stems from the fact that kernel memory corruption can be leveraged to gain control over the system's most critical processes, making this vulnerability particularly concerning for server environments or systems where multiple users may have access to the local machine. The attack surface is limited to systems running the affected kernel version with the specific Xircom PCMCIA driver loaded, but this includes various embedded systems, older workstation configurations, and specialized industrial equipment.
Mitigation strategies for CVE-2023-1670 should prioritize immediate kernel updates from the affected distribution vendors, as most modern Linux distributions have already patched this vulnerability in their security updates. System administrators should ensure that all kernel packages are updated to versions containing the appropriate memory management fixes for the Xircom PCMCIA driver. Additionally, the implementation of kernel module blacklisting for the vulnerable driver can provide an immediate workaround if patching is not immediately feasible. Organizations should conduct comprehensive inventory assessments to identify all systems running affected kernel versions and hardware configurations that may be exposed to this vulnerability. The ATT&CK framework categorizes this vulnerability under T1068, which covers 'Exploitation for Privilege Escalation', highlighting the potential for local privilege escalation through kernel-level memory corruption. Systems with enhanced security controls such as kernel address space layout randomization and stack canaries should provide additional defense-in-depth measures, though these protections are not sufficient to prevent exploitation entirely. Regular vulnerability scanning and patch management processes should include verification of kernel driver configurations to ensure that legacy PCMCIA support is only enabled when absolutely necessary for operational requirements.