CVE-2025-12052 is a vulnerability classified under CWE-787 (Out-of-bounds Write) found in Insyde Software's InsydeH2O tools, which are commonly used in firmware and BIOS implementations. The root cause lies in the drivers within these tool packages that use the RTL_QUERY_REGISTRY_DIRECT flag to read registry values. This flag is intended for direct registry queries but, in this case, the code does not properly validate or bound-check the size of the data read from the registry. An untrusted user-mode application with low privileges can manipulate the registry value to cause a buffer overflow, leading to an out-of-bounds write condition. This memory corruption can be exploited to execute arbitrary code with elevated privileges, compromise system integrity, or cause denial of service by crashing critical system components. The vulnerability requires local access with low privileges (PR:L) but does not require user interaction (UI:N), making exploitation feasible in environments where users have limited system access but no administrative rights. The CVSS v3.1 base score of 7.8 reflects the high impact on confidentiality, integrity, and availability (all rated high), combined with low attack complexity and privileges required. No public exploits have been reported yet, but the potential for exploitation is significant given the nature of firmware-level code and the critical role of InsydeH2O in system boot processes. The affected versions are not explicitly listed, but organizations using InsydeH2O tools should assume all current versions prior to a patch are vulnerable. The vulnerability was reserved in October 2025 and published in January 2026, indicating recent discovery and disclosure. Because firmware and BIOS-level vulnerabilities can bypass many traditional security controls, this issue poses a serious threat to system security and stability.

For European organizations, the impact of CVE-2025-12052 can be severe. The vulnerability enables local privilege escalation from low-privileged user-mode applications to potentially full system control, compromising confidentiality, integrity, and availability of affected systems. This can lead to unauthorized access to sensitive data, persistent malware implantation at firmware level, and disruption of critical services. Sectors such as manufacturing, telecommunications, finance, and government agencies that rely on devices with InsydeH2O firmware are particularly at risk. The ability to exploit this vulnerability without user interaction increases the risk of automated or stealthy attacks within corporate networks. Additionally, firmware-level compromise is difficult to detect and remediate, often requiring firmware re-flashing or hardware replacement, which can cause operational downtime and increased costs. The threat is amplified in environments with shared or multi-user systems where untrusted users have local access. European organizations with stringent regulatory requirements for data protection and system integrity may face compliance risks if this vulnerability is exploited. Overall, the vulnerability could facilitate advanced persistent threats (APTs) targeting critical infrastructure and high-value assets in Europe.

To mitigate CVE-2025-12052, European organizations should take the following specific actions: 1) Immediately restrict local user privileges to the minimum necessary, preventing untrusted users from accessing or modifying registry keys related to InsydeH2O tools. 2) Implement strict application whitelisting and endpoint protection to detect and block unauthorized attempts to manipulate registry values or execute suspicious code. 3) Monitor registry access patterns and system logs for unusual activity indicative of exploitation attempts. 4) Coordinate with Insyde Software to obtain and deploy firmware or driver patches as soon as they become available; maintain close communication with vendors for timely updates. 5) For critical systems, consider firmware integrity verification and secure boot mechanisms to detect unauthorized firmware modifications. 6) Conduct thorough inventory and asset management to identify all devices using InsydeH2O tools and prioritize patching accordingly. 7) Educate IT and security teams about the risks of local privilege escalation vulnerabilities and the importance of limiting local access. 8) In environments where patching is delayed, consider isolating vulnerable systems or applying compensating controls such as enhanced network segmentation. These measures go beyond generic advice by focusing on local access control, registry monitoring, and firmware integrity specific to this vulnerability.