CVE-2025-41226
📋 TL;DR
This CVE describes a denial-of-service vulnerability in VMware ESXi where an authenticated attacker with guest operation privileges can crash guest VMs running VMware Tools. The vulnerability affects ESXi systems with guest operations enabled, requiring the attacker to already have authenticated access through vCenter Server or ESXi.
💻 Affected Systems
- VMware ESXi
⚠️ 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
Complete denial-of-service for multiple guest VMs, disrupting business operations and potentially causing data loss if services crash during critical operations.
Likely Case
Targeted disruption of specific guest VMs by authenticated malicious insiders or compromised accounts, leading to service interruptions.
If Mitigated
Limited impact due to restricted guest operation privileges and proper access controls limiting who can trigger the vulnerability.
🎯 Exploit Status
Exploitation requires existing authentication and guest operation privileges, making it primarily an insider threat or post-compromise attack.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Check Broadcom advisory for specific patched versions
Vendor Advisory: https://support.broadcom.com/web/ecx/support-content-notification/-/external/content/SecurityAdvisories/0/25717
Restart Required: Yes
Instructions:
1. Review Broadcom advisory for affected versions. 2. Download and apply the appropriate ESXi patch from VMware. 3. Reboot ESXi host after patching. 4. Verify patch installation through ESXi version check.
🔧 Temporary Workarounds
Disable guest operations
allDisable guest operations on VMs to prevent exploitation of this vulnerability
# Via vSphere Client: VM Settings > VM Options > Advanced > Edit Configuration > Add row with name 'guest.command.enabled' and value 'false'
Restrict guest operation privileges
allLimit which users/roles have guest operation privileges to reduce attack surface
# Review and modify role permissions in vCenter to remove unnecessary guest operation privileges
🧯 If You Can't Patch
- Implement strict access controls to limit guest operation privileges to essential personnel only
- Monitor for unusual guest operation activities and implement network segmentation to isolate management interfaces
🔍 How to Verify
Check if Vulnerable:
Check ESXi version against Broadcom advisory. Verify if guest operations are enabled on VMs (VM Settings > VM Options > Advanced).Check Version:
esxcli system version getVerify Fix Applied:
Confirm ESXi version is updated to patched version. Verify guest operations remain disabled if using workaround.📡 Detection & Monitoring
Log Indicators:
- Unusual guest operation requests in vCenter/ESXi logs
- Multiple VM crashes within short timeframes
- Failed guest operation attempts
Network Indicators:
- Unusual traffic patterns to/from vCenter management interfaces
- Multiple connection attempts to guest operation ports
SIEM Query:
source="vcenter" AND (event_type="guest.operation" OR message="VM crash") | stats count by src_ip, user