CVE-2023-20854: VMware Workstation Privilege Escalation

CVE-2023-20854 Overview

CVE-2023-20854 is an arbitrary file deletion vulnerability affecting VMware Workstation on Windows systems. A malicious actor with local user privileges on the victim's machine may exploit this vulnerability to delete arbitrary files from the file system of the machine on which Workstation is installed. This vulnerability falls under CWE-269 (Improper Privilege Management), indicating that the issue stems from insufficient access control mechanisms within the VMware Workstation application.

Critical Impact

Successful exploitation allows attackers with local access to delete arbitrary files on the host system, potentially causing system instability, data loss, or enabling further attack chains through the removal of security controls and audit logs.

Affected Products

• VMware Workstation 17.0
• VMware Workstation running on Microsoft Windows
• Host systems with VMware Workstation installed

Discovery Timeline

• 2023-02-03 - CVE-2023-20854 published to NVD
• 2025-03-26 - Last updated in NVD database

Technical Details for CVE-2023-20854

Vulnerability Analysis

This arbitrary file deletion vulnerability in VMware Workstation represents a significant security risk for Windows host systems running the virtualization software. The vulnerability allows a local attacker with standard user privileges to delete files that would normally require elevated permissions to remove. The attack requires local access to the system but does not require any user interaction to execute successfully.

The scope of this vulnerability extends beyond the vulnerable component itself, potentially affecting the underlying Windows operating system. While confidentiality is not directly impacted, the integrity and availability implications are severe—unauthorized file deletion can corrupt system operations, remove security controls, delete audit trails, or cause denial of service conditions on the host machine.

Root Cause

The root cause of CVE-2023-20854 is improper privilege management (CWE-269) within VMware Workstation's file handling operations. The vulnerability exists because the application performs file operations with elevated privileges without properly validating whether the requesting user should have permission to delete the target files. This creates a privilege boundary violation where a low-privileged local user can leverage VMware Workstation's elevated context to delete files they would otherwise be unable to remove.

Attack Vector

The attack vector for this vulnerability is local, requiring the attacker to have existing user privileges on the target machine where VMware Workstation is installed. The exploitation does not require any special conditions or user interaction, making it straightforward to execute once local access is obtained. An attacker could chain this vulnerability with other attacks—for example, first gaining initial access through phishing or another vulnerability, then using this file deletion capability to remove security software, clear logs, or corrupt system files to achieve persistence or further compromise the system.

The vulnerability mechanism involves the attacker crafting requests to VMware Workstation that reference arbitrary file paths. Due to the improper privilege management, Workstation processes these requests in an elevated context without verifying that the requesting user has legitimate deletion rights to the specified files. Technical details regarding the specific exploitation method can be found in the VMware Security Advisory VMSA-2023-0003.

Detection Methods for CVE-2023-20854

Indicators of Compromise

• Unexpected deletion of system files, security software components, or Windows event logs
• VMware Workstation processes accessing or modifying files outside of normal virtual machine directories
• Suspicious file system activity from vmware.exe or related VMware processes targeting system-critical paths
• Missing audit logs or gaps in file system monitoring records

Detection Strategies

• Monitor file system activity from VMware Workstation processes for deletion operations targeting files outside standard VM directories
• Implement file integrity monitoring (FIM) on critical system files, security software, and audit logs
• Enable Windows Security auditing for file deletion events and correlate with VMware process activity
• Deploy endpoint detection rules that alert on privilege escalation patterns involving VMware components

Monitoring Recommendations

• Configure real-time alerting for unexpected file deletions by VMware Workstation-related processes
• Establish baseline file access patterns for VMware Workstation and alert on deviations
• Implement SentinelOne's behavioral AI detection to identify suspicious file deletion patterns that deviate from normal virtualization operations
• Monitor for rapid sequential file deletions or targeting of security-relevant file paths

How to Mitigate CVE-2023-20854

Immediate Actions Required

• Update VMware Workstation to the latest patched version as specified in VMSA-2023-0003
• Review and restrict local user access to systems running VMware Workstation
• Implement application control policies to limit which users can execute VMware Workstation
• Enable comprehensive file system auditing on Windows hosts running vulnerable versions

Patch Information

VMware has released a security update to address this vulnerability. Administrators should consult the VMware Security Advisory VMSA-2023-0003 for specific patch versions and upgrade instructions. Organizations should prioritize patching VMware Workstation installations, particularly on systems that are accessible to multiple users or in environments where local user privileges may be compromised.

Workarounds

• Restrict local access to systems running VMware Workstation to only trusted administrators until patches can be applied
• Implement strict file system permissions and access controls on critical system files and directories
• Deploy endpoint protection solutions like SentinelOne to detect and block suspicious file deletion attempts
• Consider temporarily uninstalling VMware Workstation from high-risk systems until the patch is deployed

# Verify VMware Workstation version to check if patching is required
# Run from Windows Command Prompt
"C:\Program Files (x86)\VMware\VMware Workstation\vmware.exe" --version

# Enable Windows file auditing for monitoring deletion events
auditpol /set /subcategory:"File System" /success:enable /failure:enable