CVE-2025-10451 is a vulnerability classified under CWE-787 (Out-of-bounds Write) found in Insyde Software's InsydeH2O BIOS firmware, particularly impacting HP feature versions before 20C1. The vulnerability arises due to an unchecked output buffer within the System Management Mode (SMM) code, which is a highly privileged execution environment in modern CPUs responsible for low-level system management tasks. An out-of-bounds write in this context can lead to arbitrary code execution within SMM, allowing an attacker to corrupt SMM memory. Since SMM operates at a higher privilege level than the operating system and hypervisor, successful exploitation can compromise the confidentiality, integrity, and availability of the entire system. The vulnerability requires local access with high privileges (PR:H) but does not require user interaction (UI:N). The attack vector is local (AV:L), meaning an attacker must already have substantial access to the system. The vulnerability has a CVSS v3.1 base score of 8.2, reflecting its high impact and exploitability. No public patches or known exploits are currently available, but the risk remains significant due to the critical nature of SMM. The vulnerability affects HP devices using InsydeH2O BIOS versions before 20C1, which are commonly found in enterprise and government hardware. The unchecked buffer handling flaw could be exploited by malicious insiders or attackers who have gained elevated privileges to execute arbitrary code at the highest privilege level, potentially bypassing OS-level security controls and compromising the entire system firmware.

For European organizations, this vulnerability poses a severe risk because it targets the BIOS firmware layer, which is foundational to system security. Exploitation can lead to persistent firmware-level compromise that is difficult to detect and remediate, potentially allowing attackers to maintain long-term control over affected systems. Confidential data could be exfiltrated or manipulated, system integrity could be undermined, and availability could be disrupted through firmware corruption. Organizations in sectors with high-value targets such as finance, government, critical infrastructure, and manufacturing are particularly at risk. The requirement for local high-privilege access limits remote exploitation but does not eliminate risk, especially from insider threats or attackers who have already breached perimeter defenses. The lack of current patches increases the window of exposure. Given the widespread use of HP hardware with InsydeH2O BIOS in Europe, the vulnerability could affect a broad range of endpoints, servers, and workstations, amplifying potential operational and reputational damage.

European organizations should immediately inventory their hardware to identify systems running HP devices with InsydeH2O BIOS versions prior to 20C1. Until a patch is released, strict access control policies must be enforced to limit local administrative privileges and prevent unauthorized physical or remote access to affected systems. Employ endpoint detection and response (EDR) solutions capable of monitoring for suspicious activities indicative of firmware tampering or privilege escalation. Implement hardware-based security features such as Trusted Platform Module (TPM) and BIOS write protections to reduce the risk of firmware modification. Regularly audit and monitor system logs for anomalies related to SMM or BIOS behavior. Engage with HP and Insyde Software for timely updates and apply firmware patches as soon as they become available. Additionally, consider network segmentation to isolate critical systems and reduce the risk of lateral movement by attackers who gain local access.