CVE-2025-41241 in vCenter Server
Summary
by MITRE • 07/29/2025
VMware vCenter contains a denial-of-service vulnerability. A malicious actor who is authenticated through vCenter and has permission to perform API calls for guest OS customisation may trigger this vulnerability to create a denial-of-service condition.
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Analysis
by VulDB Data Team • 08/06/2025
This vulnerability exists within VMware vCenter Server, a critical component of the VMware vSphere platform that serves as the central management interface for virtual infrastructure. The flaw specifically affects the guest operating system customization functionality, which allows administrators to automate the configuration of virtual machine guest operating systems during deployment or cloning operations. The vulnerability arises from insufficient input validation and sanitization within the API handling mechanisms that process guest OS customization requests. An authenticated attacker with appropriate permissions can exploit this weakness by crafting malicious API calls that trigger an unhandled exception or resource exhaustion condition within the vCenter Server process.
The technical implementation of this vulnerability stems from improper validation of user-supplied parameters during guest OS customization operations. When the vCenter Server processes these API requests, it fails to adequately sanitize or validate certain input fields that control the customization process, particularly those related to configuration scripts, network settings, or system parameters. This lack of input validation creates a path for attackers to inject malformed data that causes the underlying service to crash or enter a non-responsive state. The vulnerability is classified as a denial-of-service condition because it disrupts the normal operation of the vCenter Server, preventing legitimate users from performing essential management functions. The issue manifests as a complete service interruption that requires manual intervention to restore normal operations, typically involving server restarts or manual cleanup of corrupted processes.
The operational impact of this vulnerability extends beyond simple service disruption to encompass broader infrastructure management challenges. Organizations relying on vCenter for virtual machine provisioning, configuration management, and orchestration may experience significant downtime during exploitation attempts, particularly in environments where automated deployment workflows depend on guest OS customization features. The vulnerability affects the availability of critical management interfaces, potentially blocking administrators from performing routine maintenance tasks, deploying new virtual machines, or managing existing guest operating systems. Given that vCenter serves as the central control point for large virtual infrastructures, a successful exploitation could cascade into wider operational disruptions affecting multiple virtual machines and services dependent on the compromised management platform.
Organizations should implement immediate mitigations including applying the latest VMware patches and updates to address the vulnerability, as well as implementing network segmentation and access controls to limit the number of authenticated users with guest OS customization permissions. Security teams should also consider implementing monitoring solutions to detect unusual API call patterns that may indicate exploitation attempts, and establish incident response procedures for rapid recovery from service disruption events. The vulnerability aligns with CWE-20, which describes improper input validation, and represents a significant risk in environments where privileged access is not properly controlled. From an ATT&CK framework perspective, this vulnerability maps to techniques involving service disruption and credential abuse, as exploitation requires authenticated access with specific permissions. Organizations should also review their privilege management policies to ensure that guest OS customization permissions are granted only to trusted administrators and that regular access reviews are conducted to minimize the attack surface.