CVE-2025-22224: VMware ESXi Privilege Escalation Flaw

CVE-2025-22224 Overview

VMware ESXi, and Workstation contain a TOCTOU (Time-of-Check Time-of-Use) vulnerability that leads to an out-of-bounds write. A malicious actor with local administrative privileges on a virtual machine may exploit this issue to execute code as the virtual machine's VMX process running on the host.

Critical Impact

This vulnerability allows an attacker to execute code with elevated privileges, affecting system stability and data integrity.

Affected Products

• VMware ESXi
• VMware Cloud Foundation
• VMware Telco Cloud Infrastructure

Discovery Timeline

• Not Available - Vulnerability discovered by Not Available
• Not Available - Responsible disclosure to VMware
• Not Available - CVE CVE-2025-22224 assigned
• Not Available - VMware releases security patch
• 2025-03-04 - CVE CVE-2025-22224 published to NVD
• 2025-10-30 - Last updated in NVD database

Technical Details for CVE-2025-22224

Vulnerability Analysis

The vulnerability arises from a classic TOCTOU race condition, leading to an out-of-bounds write. This occurs during the handling of virtual machine files where an attacker could manipulate file states between the time of check and use, allowing execution of arbitrary code under VMX process privileges.

Root Cause

The root cause is the improper handling of critical file operations that are vulnerable to race conditions, specifically in timing checks and subsequent uses without adequate locks or compensations.

Attack Vector

The attack requires local administrative privileges on a virtual machine, exploiting the race condition to achieve code execution on the host.

// Example exploitation code (sanitized)
#include <stdio.h>
#include <pthread.h>

void *race_condition(void *data) {
    // Construct race condition exploit here
    printf("Exploit race condition\n");
    return NULL;
}

int main() {
    pthread_t t1, t2;
    // Start racing threads
    pthread_create(&t1, NULL, race_condition, NULL);
    pthread_create(&t2, NULL, race_condition, NULL);
    pthread_join(t1, NULL);
    pthread_join(t2, NULL);
    return 0;
}

Detection Methods for CVE-2025-22224

Indicators of Compromise

• Unexpected VMX process crashes
• Suspicious file access patterns on virtual machine disks
• Log entries indicating rapid configuration changes

Detection Strategies

Employ real-time monitoring to detect unusual access or modification patterns within VM configuration files. Leverage file integrity monitoring tools to capture unauthorized changes.

Monitoring Recommendations

Configure alerts for anomalies in file permissions or access rates on VMX files. Use intrusion detection systems to flag rapid consecutive access attempts on sensitive resources.

How to Mitigate CVE-2025-22224

Immediate Actions Required

• Restrict local administrative access to critical VM environments
• Implement file integrity monitoring
• Conduct regular security audits on VM infrastructure

Patch Information

Ensure all systems are updated with the latest security patches provided by VMware, available on their official advisory.

Workarounds

If patching is not immediately feasible, consider restricting VMX file operations to minimize risk.

# Configuration example
chmod -R 600 /vmfs/volumes/*/*.vmx