CVE-2025-12052 is a vulnerability classified under CWE-787 (Out-of-bounds Write) affecting Insyde Software's InsydeH2O tools, which are commonly used in firmware and BIOS environments. The root cause lies in the drivers within these tool packages that utilize the RTL_QUERY_REGISTRY_DIRECT flag to read registry values. This method can be exploited by an untrusted user-mode application to cause a buffer overflow due to improper bounds checking. The overflow can lead to arbitrary code execution with elevated privileges, as the driver operates at a higher privilege level than the attacker’s user-mode application. The vulnerability requires local access with low privileges (PR:L) but does not require user interaction (UI:N), making it a potent local privilege escalation vector. The CVSS v3.1 score of 7.8 reflects high impact on confidentiality, integrity, and availability (C:H/I:H/A:H), with low attack complexity (AC:L). No public exploits have been reported yet, but the nature of the vulnerability suggests that once exploit code is developed, it could be used to compromise systems by escalating privileges and potentially implanting persistent malware or disrupting system operations. The affected versions are not explicitly listed but are implied to be those using vulnerable InsydeH2O tool packages. The vulnerability was reserved in October 2025 and published in January 2026, indicating recent discovery and disclosure. Given the critical role of firmware and BIOS in system security, exploitation could undermine foundational security controls, making this a significant threat to affected environments.

For European organizations, the impact of CVE-2025-12052 is considerable. The vulnerability enables local attackers with limited privileges to escalate their rights to higher privilege levels, potentially gaining full control over affected systems. This can lead to unauthorized access to sensitive data, modification or destruction of critical system files, and disruption of business operations. In sectors such as finance, healthcare, manufacturing, and government, where firmware integrity is crucial, exploitation could result in severe confidentiality breaches, operational downtime, and loss of trust. Additionally, compromised firmware or BIOS components can be used to establish persistent threats that are difficult to detect and remediate. The requirement for local access limits remote exploitation but does not eliminate risk, especially in environments with many users or where endpoint security is weak. The absence of known exploits currently provides a window for proactive defense, but organizations must act swiftly to prevent potential future attacks. The high CVSS score underscores the severity and potential widespread impact if exploited.

1. Restrict local user permissions rigorously to minimize the number of users who can execute or interact with InsydeH2O tools or related drivers. 2. Implement application whitelisting and endpoint protection solutions that monitor and block unauthorized registry access attempts, particularly those involving RTL_QUERY_REGISTRY_DIRECT flag usage. 3. Monitor system logs and registry access patterns for anomalies indicative of exploitation attempts, focusing on local user activities. 4. Prepare for rapid deployment of patches or updates from Insyde Software once they become available; establish communication channels with vendors for timely updates. 5. Conduct firmware and BIOS integrity checks regularly to detect unauthorized modifications potentially caused by exploitation. 6. Educate IT staff and users about the risks of local privilege escalation vulnerabilities and enforce strict policies on software installation and execution. 7. Segment networks and restrict physical and logical access to critical systems to reduce the attack surface. 8. Employ advanced endpoint detection and response (EDR) tools capable of identifying suspicious behavior related to privilege escalation and registry manipulation.