CVE-2025-12050–12053: High-Risk Kernel Driver Buffer Overflow Enables Local Privilege Escalation

Vulnerability Overview

Vulnerability name: Kernel driver buffer overflow via registry access
CVE IDs: CVE-2025-12050, CVE-2025-12051, CVE-2025-12052, CVE-2025-12053
Vulnerability type: Kernel-mode buffer overflow (out-of-bounds write)
Severity: High
CVSS score: 7.8 (High)
Attack vector: Local
Privileges required: Low
User interaction: None
Impact: System crash, local privilege escalation, potential kernel-level code execution

What this vulnerability is about

This vulnerability exists in certain Windows kernel drivers that are installed as part of firmware-related or OEM system utility tools. These drivers read configuration data directly from the Windows Registry while running in kernel mode.

The problem is that the drivers do not properly validate the size or structure of the registry data before copying it into memory. If the registry value is larger than expected or intentionally malformed, the driver may write past the allocated memory buffer.

Because this happens in kernel space, the consequences are far more serious than a typical user-mode crash. A successful overflow can corrupt kernel memory, cause a blue screen, or—under specific conditions—allow an attacker to gain SYSTEM-level privileges.

This is not a remote vulnerability. An attacker must already have local access to the system, but they do not need administrator privileges to trigger the vulnerable behavior.

Why this matters in real environments

Kernel drivers are among the most trusted components on a Windows system. When a kernel driver is vulnerable:

Endpoint security tools can be bypassed
Privilege boundaries are broken
Persistence becomes trivial
Full system compromise is possible

This issue is especially relevant for:

Developer workstations
Shared lab machines
CI/CD or imaging systems
Environments where OEM or firmware tools are installed but rarely updated

Even though exploitation requires local access, attackers often gain local access first through phishing, malware loaders, or compromised credentials. This vulnerability then becomes a second-stage escalation path.

How exploitation would work

The following description explains behavior only. It does not include exploit code or actionable instructions.

A low-privileged user or process writes a specially crafted value into a registry location that the vulnerable driver reads during initialization or operation.
The value is intentionally larger than what the driver expects.
When the driver loads or accesses that registry key, it copies the data into a fixed-size kernel buffer.
Because no proper bounds check is performed, memory outside the buffer is overwritten.
Depending on what is overwritten:
- The system may immediately crash (blue screen)
- Kernel structures may be corrupted
- Execution flow may be redirected, allowing privilege escalation

In most real-world cases, exploitation would start as denial of service and evolve into privilege escalation as attackers refine memory control.

Exploit and PoC availability

There is no publicly available, reliable exploit code at the time of disclosure.
No confirmed exploitation has been observed in the wild.
The vulnerability is technically exploitable, but exploitation requires kernel knowledge and careful memory manipulation.
Attackers with exploit-development skills could weaponize this over time, especially if the driver is widely deployed.

From a defender’s perspective, this means:

Patch before a PoC appears
Monitor closely for driver abuse
Treat presence of the vulnerable driver as a risk indicator

How to detect exploitation or attempted abuse

1. Detect vulnerable driver presence (highest value)

Look for the following driver files on endpoints:

H2OFFT32.sys
H2OFFT64.sys
egwindrv.sys
egwindrvx64.sys

Any system running these drivers before applying the vendor update should be considered vulnerable.

2. Monitor kernel driver loads

Enable kernel driver load logging (for example via Sysmon or EDR telemetry).

What to alert on:

Driver loads involving the filenames above
Drivers loading from non-standard directories
Unsigned or improperly signed drivers
Driver loads shortly after registry modifications

Why this works:
Exploitation requires the vulnerable driver to be loaded and active.

3. Watch for suspicious registry activity

Because the overflow is triggered through registry input, registry telemetry is critical.

Suspicious patterns include:

Large registry values being written shortly before a driver loads
Unusual data types or binary blobs where simple strings are expected
Registry writes performed by unexpected user processes
Repeated registry writes followed by system instability

Even if you don’t know the exact registry key, abnormally large registry values written by non-admin users are worth investigation.

4. Blue screen and crash correlation

Kernel buffer overflows frequently cause crashes during failed exploitation attempts.

Red flags:

Blue screens that reference the vulnerable driver in memory dumps
Repeated crashes on the same host after registry changes
Crashes occurring immediately after a system utility or firmware tool runs

Crash telemetry is often overlooked but is very valuable for detecting early exploit attempts.

5. EDR behavioral signals

If you use an endpoint detection platform, hunt for:

User-mode processes interacting with kernel drivers unexpectedly
Non-administrative users triggering driver activity
Processes that write registry data and then load or interact knowing drivers
Attempts to disable protections shortly after a driver crash or reload

Example detection logic

Driver load monitoring

Alert when a kernel driver is loaded and the filename matches known vulnerable drivers
AND the driver is unsigned or loaded from an unusual path

Registry abuse hunting

Alert when a non-admin user writes unusually large registry values
AND a kernel driver loads shortly afterward

Crash correlation

Alert when a system experiences repeated blue screens
AND the crash dump references the vulnerable driver

These detections work best when combined rather than used individually.

MITRE ATT&CK mapping

Privilege Escalation: Exploitation for Privilege Escalation
Defense Evasion: Abuse of trusted kernel components
Persistence (potential): Kernel driver reuse once SYSTEM access is achieved

Mitigation and remediation guidance

Immediate actions

Identify all systems with the affected drivers installed
Apply vendor-provided updates as soon as possible
Reboot systems after updating drivers

Short-term mitigations (if patching is delayed)

Restrict local user access on vulnerable systems
Remove unused firmware or OEM utility tools
Increase logging around driver load and registry changes

Long-term hardening

Enforce driver signature verification
Regularly inventory kernel drivers across endpoints
Treat firmware and OEM tools as security-sensitive software, not “set and forget” utilities

Official patch / upgrade link

Vendor security advisory and fixed versions:
https://www.insyde.com/security-pledge/sa-2025010

Final Takeaway

This vulnerability does not currently appear to be exploited at scale, but kernel vulnerabilities age poorly. Once exploit techniques become public, they are often reused across campaigns.

Organizations should treat this as a patch-now, hunt-after issue rather than waiting for active exploitation.