CVE-2025-12051: Driver Registry Buffer Overflow Flaw

CVE-2025-12051 Overview

CVE-2025-12051 is a buffer overflow vulnerability affecting drivers in tool packages that use the RTL_QUERY_REGISTRY_DIRECT flag to read registry values. An untrusted user-mode application may exploit this vulnerability to cause a buffer overflow, potentially leading to local privilege escalation or arbitrary code execution with elevated privileges.

Critical Impact

Local attackers with low privileges can exploit this driver-level buffer overflow to achieve high impact on confidentiality, integrity, and availability of affected systems.

Affected Products

• Insyde tool package drivers using RTL_QUERY_REGISTRY_DIRECT flag
• Systems with affected BIOS/UEFI firmware from Insyde Software

Discovery Timeline

• 2026-01-14 - CVE-2025-12051 published to NVD
• 2026-01-14 - Last updated in NVD database

Technical Details for CVE-2025-12051

Vulnerability Analysis

This vulnerability stems from improper use of the RTL_QUERY_REGISTRY_DIRECT flag in Windows kernel-mode drivers. When drivers use this flag with RtlQueryRegistryValues() to read registry data, they must allocate a buffer of sufficient size to hold the registry value. The affected drivers fail to properly validate the size of the registry data before copying it into a fixed-size buffer, creating a classic buffer overflow condition (CWE-787: Out-of-bounds Write).

The local attack vector means an attacker must have some level of access to the target system. However, only low privileges are required to trigger the vulnerability, and no user interaction is necessary. Successful exploitation allows an attacker to write beyond the bounds of the allocated buffer, potentially corrupting adjacent memory, overwriting critical kernel structures, or hijacking execution flow.

Root Cause

The root cause is the unsafe usage pattern of RTL_QUERY_REGISTRY_DIRECT in kernel-mode drivers. This flag tells the registry query function to write data directly into a caller-supplied buffer. If the driver provides a fixed-size buffer without first querying the actual size of the registry value, a malicious user-mode application can create or modify registry values to be larger than expected, triggering the overflow when the driver reads the data.

The Windows registry allows user-mode applications to write values to certain registry keys. When a privileged driver subsequently reads these user-controlled values using RTL_QUERY_REGISTRY_DIRECT without proper size validation, the attacker-controlled data overflows the kernel buffer.

Attack Vector

An attacker with local access and low privileges can exploit this vulnerability through the following attack flow:

1. Identify registry keys that are read by the vulnerable driver using RTL_QUERY_REGISTRY_DIRECT
2. Modify or create registry values with data exceeding the driver's expected buffer size
3. Trigger the driver to read the malicious registry value
4. The oversized data causes a buffer overflow in kernel memory
5. Depending on memory layout, this could lead to privilege escalation, code execution, or denial of service

Since no verified proof-of-concept code is available, the specific exploitation mechanics depend on the particular driver implementation and target registry keys. For detailed technical information, refer to the Insyde Security Advisory SA-2025010.

Detection Methods for CVE-2025-12051

Indicators of Compromise

• Unexpected modifications to registry values in keys accessed by Insyde tool drivers
• Kernel crash dumps or BSODs related to memory corruption in driver contexts
• Suspicious user-mode processes attempting to write unusually large registry values
• Anomalous driver behavior or system instability after registry modifications

Detection Strategies

• Monitor for registry write operations to keys associated with affected Insyde drivers
• Implement kernel memory integrity monitoring to detect out-of-bounds writes
• Enable Windows Defender Credential Guard and related kernel protections where available
• Deploy endpoint detection solutions capable of monitoring driver-level activity and registry manipulation patterns

Monitoring Recommendations

• Enable detailed Windows Security Event logging for registry access (Event IDs 4656, 4663)
• Configure SentinelOne to monitor for suspicious registry modification patterns targeting driver-related keys
• Implement alerts for kernel-mode exceptions or unexpected driver faults
• Review system stability logs for signs of memory corruption

How to Mitigate CVE-2025-12051

Immediate Actions Required

• Review and apply the latest security updates from Insyde Software as referenced in the security advisory
• Audit systems for the presence of affected tool package drivers
• Restrict local user access to systems with affected drivers where possible
• Implement application whitelisting to prevent unauthorized user-mode applications from running

Patch Information

Insyde Software has released security advisory SA-2025010 addressing this vulnerability. Organizations should obtain the patched drivers from their system or motherboard manufacturer, as BIOS/UEFI updates typically require vendor-specific packages. Refer to the Insyde Security Advisory SA-2025010 for detailed patch information and affected product versions.

Workarounds

• Restrict registry permissions on keys read by affected drivers to prevent modification by low-privileged users
• Remove or disable affected tool package drivers if they are not essential for system operation
• Implement strict least-privilege access controls on systems with affected firmware
• Deploy SentinelOne endpoint protection to detect and block exploitation attempts targeting this vulnerability