VMware Security Alert: Insecure File Handling in VMware Tools (CVE-2025-22247)
Introduction
Broadcom has issued a moderate-severity security advisory, VMSA-2025-0007, addressing a newly disclosed vulnerability in VMware Tools identified as CVE-2025-22247. This vulnerability affects both Windows and Linux guest operating systems and introduces a risk scenario where a non-privileged user inside a virtual machine could tamper with file operations carried out by VMware Tools. Although this flaw is not exploitable for guest-to-host escape, it may allow local privilege manipulation within the guest OS under specific conditions.
For environments that rely on VMware Tools to support virtual machine functionality or automation, especially where multiple users share access to guest workloads, this vulnerability warrants immediate review and response.
What Is It?
CVE-2025-22247 is an insecure file handling vulnerability in VMware Tools. It arises from insufficient validation of file operations carried out by the tools service under the context of the guest operating system. The flaw allows a local, non-administrative user to influence or redirect file operations performed by VMware Tools, which may execute with elevated privileges or elevated file system access.
This vulnerability affects VMware Tools prior to version 12.5.2. For Linux-based systems, affected versions of open-vm-tools remain vulnerable until updated by the relevant distribution maintainers. VMware has not indicated that this vulnerability is exploitable across guest/host boundaries, nor does it impact VM escape. Instead, the concern lies in the trust assumptions regarding how VMware Tools performs file operations in environments where multiple user contexts exist.
The issue was responsibly disclosed by Sergey Bliznyuk of Positive Technologies and has been remediated in VMware Tools version 12.5.2.
Why Does It Matter?
In isolation, CVE-2025-22247 is unlikely to be the sole enabler of a high-impact attack. However, in layered attack scenarios, this vulnerability can be leveraged to elevate privileges or bypass containment within guest operating systems. In many enterprise environments, VMware Tools is used for automation scripts, file exchange, guest introspection, and logging; functions that often involve privileged operations. A non-privileged attacker able to influence these operations could gain unintended access to local resources or interfere with system behavior in ways that facilitate persistence or escalation.
This vulnerability poses the greatest risk in environments such as:
- Shared-use or lab VMs where multiple users operate under different roles.
- Developer sandboxes where normal users operate without strict workload isolation.
- Virtual desktop infrastructure (VDI) deployments where lateral movement or privilege escalation within the guest OS is a concern.
Administrators often assume that VMware Tools operations are inherently safe or confined. This disclosure reinforces the need to validate that assumption in multi-user virtual machines and those containing sensitive operations or automation hooks.
Risk Scenarios
Although Broadcom has not released exploit code or specific PoCs, several theoretical attack paths can be constructed based on the nature of the vulnerability.
In a shared Linux development environment, a non-root user could manipulate symbolic links or file paths consumed by vmtoolsd or supporting helper scripts. If VMware Tools invokes these scripts with elevated privileges or without strict file access controls, the attacker may succeed in redirecting file output, injecting configuration changes, or hijacking log file locations.
On Windows guest systems, a user with local access may attempt to exploit race conditions or manipulate writable directories such as %TEMP% or program-specific log paths to interfere with VMware Tools operations. If any component runs under the SYSTEM context and interacts with user-controlled files without proper access controls, local privilege escalation becomes possible.
In both platforms, this form of manipulation could enable secondary actions, such as staging for privilege escalation within the guest, achieving persistence, or disrupting automation functions. Since VMware Tools is commonly used in conjunction with backup tools, guest customization scripts, or management agents, indirect consequences could include operational disruption or unintended configuration drift.
What Can I Do About It?
The most direct mitigation is to upgrade VMware Tools to version 12.5.2, which addresses the vulnerable file handling behavior. For Linux distributions using open-vm-tools, administrators should monitor the vendor-maintained package repositories and apply the update as soon as it is made available.
Where patching is not immediately possible, HUME-IT recommends validating whether any privileged scripts, log collection routines, or automated actions are triggered through VMware Tools within affected guest systems. Minimizing exposure to multi-user access in those VMs and applying strict file permissions can reduce the practical risk in the short term.
At the infrastructure level, consider reviewing the use of shared VMs or developer testbeds with VMware Tools running in elevated contexts. While many workloads are designed for single-user use, assumptions about privilege containment should be validated through testing and configuration review.
Conclusion: Bottom Line
CVE-2025-22247 is a reminder that even low-privilege users inside a VM can influence components traditionally treated as trusted. While not a guest-to-host escape, this vulnerability exposes gaps in how VMware Tools validates file operations, and by extension, how enterprises assume internal security boundaries inside guest workloads. Prompt patching and closer scrutiny of tool interactions in multi-user environments are warranted.
VMware administrators and platform security teams should incorporate this fix into their regular tooling update cycles and reassess any assumptions regarding privilege isolation inside guest systems that leverage VMware Tools.
References
- Broadcom Security Advisory (VMSA-2025-0007): https://support.broadcom.com/web/ecx/support-content-notification/-/external/content/SecurityAdvisories/0/25683
- CVE-2025-22247: https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2025-22247
- VMware Tools Documentation: https://docs.vmware.com/en/VMware-Tools/index.html
- open-vm-tools GitHub: https://github.com/vmware/open-vm-tools