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Broadcom’s VMware has disclosed critical security vulnerabilities in its virtualization products, including VMware ESXi, vCenter Server, Workstation, Fusion, and others. The most severe, CVE-2025-41225 (CVSS 8.8), allows authenticated users to execute arbitrary commands on vCenter Server by exploiting alarm creation/modification. Other vulnerabilities include:
– CVE-2025-41226 (CVSS 6.8): Denial-of-service in ESXi via guest operations.
– CVE-2025-41227 (CVSS 5.5): Denial-of-service in Workstation, Fusion, and ESXi due to memory exhaustion by non-admin guest users.
– CVE-2025-41228 (CVSS 4.3): Reflected cross-site scripting in ESXi and vCenter login pages, enabling cookie theft or redirection.
Affected products include ESXi 7.0/8.0, vCenter Server 7.0/8.0, Workstation 17.x, Fusion 13.x, and others. Patches are available (e.g., vCenter 8.0 U3e, ESXi 8.0U3se-24659227), and immediate updates are recommended as no workarounds exist.
Detail: https://lnkd.in/gfqCRGYZ
You Should Know:
1. Patch VMware Immediately
To check your VMware version and apply patches:
For ESXi:
vmware -v Check current version esxcli software vib update -d <patch-depot-url> Apply patch
For vCenter:
/usr/lib/applmgmt/support/scripts/update.py --action=list List available updates /usr/lib/applmgmt/support/scripts/update.py --action=install --patch=<patch-id> Install patch
2. Mitigate CVE-2025-41225 (Arbitrary Command Execution)
Disable unnecessary alarm triggers in vCenter:
vim-cmd vimsvc/auth/entity_permissions 'AlarmManager' Check permissions vim-cmd vimsvc/auth/roles | grep Alarm Review alarm-related roles
3. Prevent DoS Attacks (CVE-2025-41226 & CVE-2025-41227)
Limit guest operations in ESXi:
esxcli system settings advanced set -o /UserVars/GuestOperationsLimit -i 5 Set max guest ops esxcli system settings advanced list -o /UserVars/GuestOperationsLimit Verify
4. Block XSS Exploits (CVE-2025-41228)
Enable HTTP security headers in vCenter:
grep X-XSS-Protection /etc/vmware/vsphere-ui/nginx/nginx.conf Check XSS protection sed -i 's/add_header X-XSS-Protection/add_header X-XSS-Protection "1; mode=block"/' /etc/vmware/vsphere-ui/nginx/nginx.conf Enable XSS blocking service-control --restart vmware-vsphere-ui Restart service
5. Monitor Suspicious Activity
Use `esxtop` to track resource abuse:
esxtop -b -n 1 | grep -E "MEM|CPU" Check memory/CPU usage tail -f /var/log/vmware/esxihost.log Monitor logs
What Undercode Say:
This VMware vulnerability chain poses severe risks to virtualized environments. Attackers can escalate privileges, crash systems, or steal session data. Immediate patching is critical. For temporary mitigation:
– Restrict alarm modifications to admins only.
– Disable guest operations if unused.
– Enforce strict input validation on login pages.
Expected Commands for Defense:
Disable guest operations: esxcli system settings advanced set -o /UserVars/GuestOperationsEnabled -i 0 Check active sessions in vCenter: vim-cmd vimsvc/session_list Block brute-force attempts: esxcli network firewall ruleset set -e true -r httpClient
Prediction:
Unpatched VMware systems will face increased attacks, including ransomware deployment via command injection. Organizations delaying updates risk large-scale VM takeovers.
Expected Output:
VMware ESXi version: 8.0.3 Patch status: Not installed Critical vulnerabilities detected: CVE-2025-41225, CVE-2025-41226 Recommended action: Apply patch ESXi800-202505001 immediately.
References:
Reported By: Phuong Nguyen – Hackers Feeds
Extra Hub: Undercode MoN
Basic Verification: Pass ✅
