CVE-2025-41237 in Cloud Foundation
Summary
by MITRE • 07/15/2025
VMware ESXi, Workstation, and Fusion contain an integer-underflow in VMCI (Virtual Machine Communication Interface) that leads to an out-of-bounds write. A malicious actor with local administrative privileges on a virtual machine may exploit this issue to execute code as the virtual machine's VMX process running on the host. On ESXi, the exploitation is contained within the VMX sandbox whereas, on Workstation and Fusion, this may lead to code execution on the machine where Workstation or Fusion is installed.
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Analysis
by VulDB Data Team • 07/17/2025
The vulnerability identified as CVE-2025-41237 represents a critical integer underflow condition within VMware's Virtual Machine Communication Interface implementation across multiple products including ESXi, Workstation, and Fusion. This flaw exists in the VMCI subsystem responsible for facilitating communication between virtual machines and host systems, creating a pathway for privilege escalation attacks that can result in arbitrary code execution. The vulnerability stems from improper input validation within the memory management routines that handle communication interface operations, specifically when processing certain data structures that control inter-vm communication channels.
The technical exploitation of this vulnerability requires a malicious actor to possess local administrative privileges within a guest virtual machine, which represents a significant operational risk given that many organizations maintain administrative access within their virtual environments. The integer underflow occurs when the system fails to properly validate the size parameters of communication buffers, allowing an attacker to manipulate these values to cause memory corruption through out-of-bounds write operations. This memory corruption directly impacts the VMX process which operates with elevated privileges on the host system, creating a direct pathway for privilege escalation from guest-level administrative access to host-level code execution.
The operational impact of this vulnerability varies significantly based on the VMware product variant in use, with distinct implications for each deployment type. On VMware ESXi platforms, the exploitation is constrained by the VMX sandbox environment which provides some isolation, though the attack still allows for code execution within the host's virtualization layer. However, in VMware Workstation and Fusion environments, the exploitation could potentially result in code execution at the host operating system level, presenting a more severe threat vector that could compromise the entire host machine. This distinction aligns with the ATT&CK framework's privilege escalation tactics where adversaries leverage existing administrative access to gain higher-level privileges, specifically mapping to techniques involving process injection and privilege escalation through system-level vulnerabilities.
The vulnerability directly correlates to CWE-191, which identifies integer underflow conditions as a common source of memory corruption vulnerabilities, and demonstrates how improper input validation can lead to out-of-bounds memory operations. Security researchers have noted that such vulnerabilities often serve as initial access vectors for more sophisticated attacks, particularly when they enable privilege escalation from guest to host contexts. Organizations utilizing VMware products must understand that this vulnerability represents a critical threat to their virtualized infrastructure security posture, as it allows attackers to potentially compromise entire host systems from within isolated virtual machines.
Mitigation strategies for CVE-2025-41237 should prioritize immediate patch deployment from VMware, as the vendor has released security updates addressing the integer underflow condition in VMCI implementations. Network segmentation and access control measures should be strengthened to limit local administrative privileges within virtual environments, reducing the attack surface available to potential adversaries. Additionally, implementing monitoring solutions that detect anomalous VMCI communication patterns and memory access violations can provide early warning capabilities for exploitation attempts. Organizations should also consider implementing micro-segmentation within their virtualized environments to limit the potential impact of successful exploitation, particularly in ESXi deployments where the attack remains contained within the virtualization layer but still represents a significant threat to host system integrity.