CVE-2025-41236
📋 TL;DR
This CVE describes an integer-overflow vulnerability in VMware's VMXNET3 virtual network adapter that allows a malicious actor with local administrative privileges on a virtual machine to execute arbitrary code on the hypervisor host. This affects VMware ESXi, Workstation, and Fusion products. Only virtual machines using the VMXNET3 adapter are vulnerable; other virtual network adapters are not affected.
💻 Affected Systems
- VMware ESXi
- VMware Workstation
- VMware Fusion
⚠️ Manual Verification Required
This CVE does not have specific version information in our database, so automatic vulnerability detection cannot determine if your system is affected.
Why? The CVE database entry doesn't specify which versions are vulnerable (no version ranges provided by the vendor/NVD).
🔒 Custom verification scripts are available for registered users. Sign up free to download automated test scripts.
- Review the CVE details at NVD
- Check vendor security advisories for your specific version
- Test if the vulnerability is exploitable in your environment
- Consider updating to the latest version as a precaution
⚠️ Risk & Real-World Impact
Worst Case
Full host compromise allowing attacker to control the hypervisor, access all VMs, and potentially pivot to other systems.
Likely Case
Privilege escalation from VM administrator to host-level code execution, leading to data theft, VM manipulation, or lateral movement.
If Mitigated
Limited impact if proper network segmentation, least privilege, and monitoring are in place to detect and contain host compromise attempts.
🎯 Exploit Status
Exploitation requires local administrative privileges on the VM and knowledge of the vulnerability. No public exploit code is mentioned.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Check vendor advisory for specific patched versions
Vendor Advisory: https://support.broadcom.com/web/ecx/support-content-notification/-/external/content/SecurityAdvisories/0/35877
Restart Required: Yes
Instructions:
1. Review the vendor advisory for affected versions and patches. 2. Apply the appropriate patch for your VMware product. 3. Restart affected virtual machines and/or hypervisor as required.
🔧 Temporary Workarounds
Switch to non-VMXNET3 adapter
allReplace VMXNET3 virtual network adapter with a different adapter type (e.g., E1000, VMXNET, VMXNET2) on vulnerable VMs.
Power off VM
Edit VM settings
Remove VMXNET3 adapter
Add alternative adapter
Configure network settings
Power on VM
🧯 If You Can't Patch
- Restrict local administrative access to VMs using VMXNET3 adapter to trusted users only.
- Implement network segmentation to isolate VMs with VMXNET3 adapters and monitor for suspicious host-level activity.
🔍 How to Verify
Check if Vulnerable:
Check VMware product version against vendor advisory and verify if any VMs use VMXNET3 virtual network adapter.Check Version:
For ESXi: esxcli system version get; For Workstation/Fusion: Check Help > About in GUI or vendor documentation.Verify Fix Applied:
Confirm VMware product is updated to patched version and no VMs are using VMXNET3 adapter unless patched.📡 Detection & Monitoring
Log Indicators:
- Unusual process execution on hypervisor host from VM context
- VMXNET3 driver crashes or errors in VMware logs
Network Indicators:
- Anomalous network traffic from VM to hypervisor management interfaces
SIEM Query:
Search for VMware host logs with event IDs related to VMXNET3 errors or unexpected privilege escalation from VM to host.