CVE-2025-41241: VMware vCenter DoS Vulnerability

CVE-2025-41241 Overview

CVE-2025-41241 is a denial-of-service vulnerability in VMware vCenter. An authenticated actor with permission to perform API calls for guest OS customisation can trigger the flaw to disrupt service availability. The issue is tracked under CWE-754: Improper Check for Unusual or Exceptional Conditions.

Broadcom published the advisory for this issue on July 29, 2025. Exploitation requires valid vCenter authentication and elevated privileges, which limits the attacker population to insiders or actors who already hold a foothold in the management plane. No public exploit code or in-the-wild exploitation has been reported.

Critical Impact
Successful exploitation produces a denial-of-service condition affecting vCenter availability, disrupting management of the virtualization fabric and dependent automation workflows.

Affected Products

VMware vCenter Server
Broadcom VMware Cloud Foundation deployments that include vCenter
Environments exposing the guest OS customisation API to authenticated operators

Discovery Timeline

2025-07-29 - CVE-2025-41241 published to NVD
2026-04-15 - Last updated in NVD database

Technical Details for CVE-2025-41241

Vulnerability Analysis

The vulnerability resides in the guest OS customisation API path of VMware vCenter. vCenter exposes APIs that allow administrators to apply customisation specifications to guest operating systems during cloning or deployment. An authenticated actor with permission to invoke these API calls can submit input that the service fails to handle safely, producing an availability impact.

The weakness is classified as CWE-754, an improper check for unusual or exceptional conditions. In practice, the service does not properly validate or guard against a specific exceptional state reachable through the customisation API, and the resulting unhandled condition degrades or halts service operation.

The attacker requirements are non-trivial. The actor must hold valid vCenter credentials and the privilege set required to perform guest OS customisation. Confidentiality and integrity are not impacted, but availability of the vCenter management plane is degraded on successful trigger.

Root Cause

The root cause is missing or insufficient handling of exceptional conditions in the guest OS customisation API logic. When the API processes a malformed or boundary-condition customisation request, the service enters an unrecovered error state instead of rejecting the input gracefully.

Attack Vector

The attack is delivered over the network to the vCenter API endpoint. The actor authenticates, invokes the guest OS customisation API with crafted parameters, and triggers the exceptional condition. Refer to the Broadcom Security Advisory for vendor technical details.

No verified proof-of-concept code is publicly available. Synthetic exploitation code is not included here because no realCodeExamples were provided.

Detection Methods for CVE-2025-41241

Indicators of Compromise

Unexpected vCenter service crashes, hangs, or restarts correlated with guest customisation API activity
Repeated or anomalous calls to guest OS customisation endpoints from a single authenticated principal
Spikes in vpxd errors or guest customisation task failures in vCenter logs

Detection Strategies

Audit vCenter API logs for guest OS customisation calls and correlate with service availability events
Baseline normal guest customisation activity per administrator account and alert on deviations
Monitor authentication and role assignments granting VirtualMachine.Provisioning.Customize or equivalent permissions

Monitoring Recommendations

Forward vCenter logs (vpxd.log, audit logs, task and event streams) to a centralized SIEM for correlation
Alert on repeated vCenter service restarts or vpxd watchdog events within short time windows
Track privileged session activity against vCenter and flag use of customisation APIs outside change windows

How to Mitigate CVE-2025-41241

Immediate Actions Required

Apply the fixed vCenter build identified in the Broadcom Security Advisory as soon as change windows permit
Restrict guest OS customisation privileges to a minimal set of operator accounts
Enforce multi-factor authentication and strong credential hygiene on all vCenter administrative accounts

Patch Information

Broadcom has published remediation guidance and fixed versions in the Broadcom Security Advisory. Administrators should review the advisory for the specific vCenter and VMware Cloud Foundation builds that address CVE-2025-41241 and plan upgrades accordingly.

Workarounds

Limit network access to the vCenter management interface to trusted administrative networks only
Review and revoke unnecessary VirtualMachine.Provisioning.Customize permissions from operator roles
Increase monitoring on vCenter availability and customisation task telemetry until patches are deployed

bash

# Review vCenter roles granting guest OS customisation privileges
# Run from a system with PowerCLI connected to vCenter
Get-VIRole | Where-Object { $_.PrivilegeList -match 'Customize' } | \
  Select-Object Name, IsSystem, PrivilegeList

# List principals assigned roles that include customisation privileges
Get-VIPermission | Where-Object { $_.Role -in (Get-VIRole | \
  Where-Object { $_.PrivilegeList -match 'Customize' }).Name } | \
  Select-Object Principal, Role, Entity