CVE-2025-59516 Overview
CVE-2025-59516 is a local privilege escalation vulnerability in the Windows Storage VSP (Virtualization Service Provider) Driver. The flaw stems from missing authentication for a critical function, classified under [CWE-73]. An authorized attacker with low-privileged local access can exploit this weakness to elevate privileges on the affected host. Microsoft disclosed the vulnerability through the Microsoft Security Response Center (MSRC) update guide. The issue impacts a broad range of supported Windows client and server releases, including Windows 10, Windows 11, and Windows Server 2019 through 2025.
Critical Impact
A local attacker with valid credentials can elevate to SYSTEM through the Windows Storage VSP Driver, gaining full control over confidentiality, integrity, and availability of the affected host.
Affected Products
- Microsoft Windows 10 (1809, 21H2, 22H2)
- Microsoft Windows 11 (23H2, 24H2, 25H2)
- Microsoft Windows Server 2019, 2022, 2022 23H2, and 2025
Discovery Timeline
- 2025-12-09 - CVE-2025-59516 published to NVD
- 2026-06-17 - Last updated in NVD database
Technical Details for CVE-2025-59516
Vulnerability Analysis
The Windows Storage VSP Driver exposes a privileged function that fails to enforce authentication before executing sensitive operations. The Storage VSP component brokers storage requests between virtualization stacks and the host, and it operates with kernel-level trust. When a critical entry point in the driver skips the required authentication check, callers running at low integrity levels can reach code paths reserved for privileged contexts. Successful exploitation yields elevated privileges within the local host, typically resulting in SYSTEM-level execution.
The vulnerability requires local access and valid low-privileged credentials. No user interaction is needed, and the attack complexity is low. The impact spans confidentiality, integrity, and availability, making the issue suitable as a second-stage payload after initial access through phishing, malware, or credential theft.
Root Cause
The root cause is a missing authentication check on a critical function within the Storage VSP Driver, aligning with [CWE-73] (External Control of File Name or Path) as classified by Microsoft. The driver trusts caller-supplied requests without verifying that the caller possesses the required privileges. This design gap allows a standard user process to invoke functionality intended only for privileged callers, producing a direct escalation path.
Attack Vector
An attacker first obtains a foothold on the target machine as an authenticated user. The attacker then issues crafted requests to the vulnerable Storage VSP Driver interface. Because the driver does not authenticate the caller for the affected function, the request is processed with elevated authority. See the Microsoft CVE-2025-59516 Update for vendor-specific technical detail.
No verified proof-of-concept code is publicly available at the time of writing. The EPSS score is 2.289% (81.761 percentile), indicating measurable but not yet widespread exploitation likelihood.
Detection Methods for CVE-2025-59516
Indicators of Compromise
- Unexpected process lineage where standard-user processes spawn SYSTEM-level children shortly after interacting with storage driver interfaces.
- Kernel driver loads or handle-open events targeting Storage VSP Driver device objects from non-administrative user sessions.
- New service creation, scheduled task registration, or LSASS access originating from processes that recently invoked storage-related IOCTLs.
Detection Strategies
- Monitor Windows Event Log channels for anomalous privilege assignment events (Event ID 4672) tied to non-administrative accounts.
- Correlate Sysmon Event ID 1 (process creation) and Event ID 10 (process access) to identify token manipulation following storage driver activity.
- Deploy behavioral endpoint detection rules that flag local privilege escalation patterns such as integrity level jumps from Medium to System.
Monitoring Recommendations
- Enable command-line and PowerShell script block logging on all endpoints and forward to a centralized SIEM for retention and correlation.
- Baseline legitimate use of the Storage VSP Driver interfaces to reduce false positives when alerting on new callers.
- Track patch compliance across Windows 10, Windows 11, and Windows Server fleets to identify hosts that remain exposed.
How to Mitigate CVE-2025-59516
Immediate Actions Required
- Apply the Microsoft security update referenced in the MSRC advisory for CVE-2025-59516 to all affected Windows client and server systems.
- Prioritize patching for multi-tenant hosts, jump servers, and virtualization infrastructure where local users are present.
- Rotate credentials on any system suspected of prior compromise, since privilege escalation invalidates existing trust boundaries.
Patch Information
Microsoft has released security updates addressing CVE-2025-59516 through the standard Windows Update channel. Refer to the Microsoft CVE-2025-59516 Update for the specific KB articles and build numbers that correspond to each affected Windows version.
Workarounds
- No official workaround is documented by Microsoft; patching is the supported remediation path.
- Restrict interactive and remote logon rights to trusted administrative users on high-value hosts to reduce the attack surface.
- Apply the principle of least privilege and enforce application allowlisting to limit which binaries can invoke driver interfaces.
# Verify patch status on Windows hosts
Get-HotFix | Sort-Object -Property InstalledOn -Descending | Select-Object -First 20
# Confirm current build to compare against MSRC-published fixed builds
[System.Environment]::OSVersion.Version
(Get-ItemProperty 'HKLM:\SOFTWARE\Microsoft\Windows NT\CurrentVersion').UBR
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
