CVE-2025-24066 Overview
CVE-2025-24066 is a heap-based buffer overflow vulnerability in Windows Kernel-Mode Drivers. An authenticated local attacker can exploit the flaw to elevate privileges on affected Windows client and server systems. The vulnerability is tracked under CWE-122, which covers heap-based buffer overflows in memory management routines. Microsoft addressed the issue through the March 2025 security update cycle. The flaw affects a broad range of supported Windows versions, including Windows 10, Windows 11, and Windows Server 2016 through Windows Server 2025.
Critical Impact
Successful exploitation grants attackers SYSTEM-level privileges, enabling full compromise of the local host from a standard user context.
Affected Products
- Microsoft Windows 10 (versions 1507, 1607, 21H2, 22H2)
- Microsoft Windows 11 (versions 22H2, 23H2, 24H2)
- Microsoft Windows Server 2016, Server 2022 23H2, and Server 2025
Discovery Timeline
- 2025-03-11 - CVE-2025-24066 published to NVD
- 2026-06-17 - Last updated in NVD database
Technical Details for CVE-2025-24066
Vulnerability Analysis
The vulnerability resides in Windows Kernel-Mode Drivers, which operate in ring 0 with full access to system memory and hardware. A heap-based buffer overflow occurs when the driver writes data beyond the bounds of an allocated kernel pool buffer. Because the overflow happens in kernel space, corruption of adjacent kernel objects can be leveraged to overwrite function pointers, dispatch tables, or object headers. Attackers use this primitive to redirect execution to attacker-controlled code running with kernel privileges.
The vulnerability requires local access and low privileges, so it is well suited to post-compromise stages of an intrusion. Adversaries who obtain an initial foothold as a standard user commonly chain this class of driver bug to move from user to NT AUTHORITY\SYSTEM. From that point, credential theft, defense evasion, and persistence become trivial.
Root Cause
The root cause is improper validation of a length or size parameter used during a kernel pool allocation and subsequent copy operation. When the driver processes crafted input from user mode, it fails to enforce boundary checks before writing into the allocated buffer. This mismatch between allocation size and copy length results in an out-of-bounds write on the kernel heap, classified under CWE-122.
Attack Vector
Exploitation requires an authenticated local user with the ability to issue I/O control (IOCTL) requests or invoke system calls handled by the vulnerable driver. The attacker crafts input that triggers the undersized allocation and oversized write. No user interaction beyond running the attacker's binary is required. Refer to the Microsoft Security Update CVE-2025-24066 advisory for component-level technical details.
Detection Methods for CVE-2025-24066
Indicators of Compromise
- Unexpected bugchecks referencing kernel pool corruption, such as BAD_POOL_HEADER (0x00000019) or KERNEL_MODE_HEAP_CORRUPTION (0x0000013A), on otherwise stable hosts.
- Standard user processes spawning child processes running as NT AUTHORITY\SYSTEM without a legitimate service or elevation path.
- Newly dropped binaries in user-writable directories immediately followed by suspicious IOCTL traffic to kernel drivers.
Detection Strategies
- Hunt for token manipulation and process integrity level changes where a medium-integrity process transitions to a system-integrity token.
- Correlate Windows Error Reporting events and Event ID 1001 crash dumps against processes that recently interacted with kernel-mode drivers.
- Baseline legitimate use of vulnerable driver device objects and alert on anomalous handle opens from non-administrative accounts.
Monitoring Recommendations
- Enable kernel pool tracing on high-value hosts using Driver Verifier during triage of suspected exploitation attempts.
- Forward Sysmon Event ID 1 (process creation) and Event ID 10 (process access) to a centralized platform for privilege-escalation analytics.
- Track patch compliance for the March 2025 Windows security update across all endpoints and servers.
How to Mitigate CVE-2025-24066
Immediate Actions Required
- Apply the March 2025 cumulative security update from Microsoft to all affected Windows client and server versions without delay.
- Prioritize patching on multi-user systems such as Remote Desktop Session Hosts, Citrix servers, and jump boxes where local users are common.
- Restrict local logon rights and remove unnecessary interactive accounts from endpoints and servers.
Patch Information
Microsoft has released fixes through the standard Windows Update channel. Consult the Microsoft Security Update CVE-2025-24066 advisory for the specific KB article and build numbers for each supported Windows release.
Workarounds
- No official workaround is published; patching is the required remediation path.
- Enforce application allowlisting with Windows Defender Application Control or AppLocker to block execution of unauthorized local exploit binaries.
- Reduce local attack surface by disabling non-essential third-party drivers and blocking known vulnerable drivers with the Microsoft Vulnerable Driver Blocklist.
# Verify installed updates and blocklist status on a Windows host
Get-HotFix | Sort-Object -Property InstalledOn -Descending | Select-Object -First 20
Citrix
Get-CimInstance -ClassName Win32_QuickFixEngineering | Where-Object { $_.HotFixID -like 'KB*' }
# Confirm Microsoft Vulnerable Driver Blocklist is enabled (Windows 11 / Server 2022+)
Get-MpComputerStatus | Select-Object -Property AMServiceEnabled, IsTamperProtected
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
