CVE-2024-22251: VMware Workstation Info Disclosure Flaw

CVE-2024-22251 Overview

CVE-2024-22251 is an out-of-bounds read vulnerability affecting VMware Workstation and Fusion virtualization products. The vulnerability exists within the USB CCID (chip card interface device) implementation, which handles smart card communications between the host and guest virtual machines. A malicious actor with local administrative privileges on a virtual machine may exploit this flaw to trigger an out-of-bounds read condition, potentially leading to information disclosure from the host system's memory.

Critical Impact

Local administrators within a guest VM can exploit this vulnerability to read sensitive information beyond intended memory boundaries, potentially exposing host system data or cryptographic materials.

Affected Products

• VMware Workstation (versions prior to patched release)
• VMware Fusion (versions prior to patched release)
• Apple macOS (as a host platform for VMware Fusion)

Discovery Timeline

• 2024-02-29 - CVE-2024-22251 published to NVD
• 2025-06-10 - Last updated in NVD database

Technical Details for CVE-2024-22251

Vulnerability Analysis

This vulnerability is classified as CWE-125 (Out-of-Bounds Read), a memory corruption flaw where the application reads data from a location outside the intended buffer boundaries. In the context of VMware's USB CCID implementation, the vulnerable code fails to properly validate buffer boundaries when processing USB CCID communications, allowing read operations to access memory beyond allocated buffer limits.

The out-of-bounds read condition requires local administrative privileges within a guest virtual machine to exploit. This attack vector indicates that an attacker must first compromise or have legitimate administrative access to a VM before they can leverage this vulnerability. The information disclosure potential makes this particularly concerning in multi-tenant environments or scenarios where virtual machines process sensitive data.

Root Cause

The root cause of CVE-2024-22251 lies in improper boundary checking within the USB CCID device emulation code. When handling chip card interface device communications, the virtualization layer fails to adequately validate the size and offset parameters of read operations. This allows crafted USB CCID requests to read memory contents beyond the intended buffer boundaries, exposing potentially sensitive host memory data to the guest VM context.

Attack Vector

The attack requires local access to a virtual machine with administrative privileges. An attacker would need to:

1. Obtain administrative access to a guest virtual machine running on VMware Workstation or Fusion
2. Craft malicious USB CCID requests with manipulated size or offset parameters
3. Send these requests through the USB CCID emulation interface
4. Trigger out-of-bounds read operations that return host memory contents
5. Analyze the disclosed information for sensitive data such as memory layout, cryptographic keys, or other confidential information

The vulnerability exploitation is limited to information disclosure with high confidentiality impact, but does not directly enable code execution or system integrity compromise.

Detection Methods for CVE-2024-22251

Indicators of Compromise

• Unusual USB CCID device activity or repeated attach/detach cycles within guest VMs
• Abnormal memory access patterns in VMware process monitoring
• Guest VMs exhibiting unexpected smart card or USB device enumeration behavior
• Log entries indicating USB CCID device errors or malformed requests

Detection Strategies

• Monitor VMware process memory access patterns for anomalous read operations
• Implement host-based intrusion detection to identify unusual USB device emulation activity
• Review VM logs for repeated USB CCID initialization or error conditions
• Deploy endpoint detection capabilities to identify exploitation attempts targeting virtualization components

Monitoring Recommendations

• Enable verbose logging for USB device emulation in VMware Workstation and Fusion
• Implement real-time monitoring of virtualization host processes for memory access anomalies
• Configure alerts for unusual USB device activity originating from guest virtual machines
• Establish baseline USB CCID usage patterns to identify deviations that may indicate exploitation

How to Mitigate CVE-2024-22251

Immediate Actions Required

• Update VMware Workstation and Fusion to the latest patched versions immediately
• Review and restrict administrative access within guest virtual machines
• Disable USB CCID passthrough if not required for business operations
• Audit virtual machine configurations to identify unnecessary USB device access

Patch Information

VMware has released security updates addressing this vulnerability. Administrators should consult the VMware Security Advisory VMSA-2024-0005 for specific version information and download links for patched releases. Apply updates to all VMware Workstation and Fusion installations in the environment.

Workarounds

• Disable USB CCID device emulation in virtual machine settings if smart card functionality is not required
• Restrict administrative access within guest VMs to limit potential attack surface
• Implement network segmentation to isolate virtual machines handling sensitive workloads
• Consider using alternative smart card readers with direct host passthrough instead of emulated CCID devices

# Disable USB controller in VMware VM configuration
# Edit the .vmx configuration file and add:
usb.present = "FALSE"

# Or to specifically disable USB CCID while keeping other USB:
usb.ccid.present = "FALSE"