CVE-2024-52880 is a high-severity vulnerability affecting multiple versions of the InsydeH2O UEFI firmware kernel, specifically versions prior to 05.29.50 (kernel 5.2), 05.38.50 (kernel 5.3), 05.46.50 (kernel 5.4), 05.54.50 (kernel 5.5), 05.61.50 (kernel 5.6), and 05.70.50 (kernel 5.7). The vulnerability resides in the VariableRuntimeDxe driver, particularly in the SecureBootHandler function. This function uses the parameters DataSize and VariableNameSize to verify whether the data or variable name are within the buffer boundaries. However, these parameters are supplied by the caller and are not validated internally, which means they cannot be trusted. This lack of proper input validation can lead to out-of-bounds memory access or buffer overflows, potentially allowing an attacker with high privileges to manipulate Secure Boot variables improperly. The vulnerability is classified under CWE-20 (Improper Input Validation), indicating that the root cause is the failure to validate external input correctly. The CVSS v3.1 base score is 7.9, reflecting a high severity due to the potential for significant confidentiality and integrity impact without requiring user interaction, but requiring high privileges and local access. The scope is changed, meaning the vulnerability can affect components beyond the initially vulnerable code. Although no known exploits are currently reported in the wild, the vulnerability's nature suggests that exploitation could allow an attacker to bypass Secure Boot protections, potentially leading to persistent firmware-level compromise or unauthorized firmware modifications. Since Secure Boot is a critical security feature designed to ensure only trusted firmware and OS loaders execute, this vulnerability undermines the trustworthiness of the platform's boot process.

For European organizations, the impact of CVE-2024-52880 can be severe, especially for those relying on devices using InsydeH2O firmware, which is common in many laptops and embedded systems. Successful exploitation could allow attackers with local high privileges to bypass Secure Boot protections, enabling the installation of persistent, stealthy malware at the firmware level. This could lead to long-term compromise that is difficult to detect or remediate, threatening the confidentiality and integrity of sensitive data and critical systems. Sectors such as finance, government, healthcare, and critical infrastructure in Europe could face significant risks, as firmware-level compromises can facilitate espionage, sabotage, or ransomware attacks. The requirement for high privileges and local access limits the attack vector to insiders or attackers who have already compromised the system to some extent, but the elevated impact of firmware compromise makes this vulnerability particularly dangerous. Additionally, the inability to trust Secure Boot undermines the security assurances of endpoint protection strategies, potentially affecting compliance with European cybersecurity regulations such as NIS2 and GDPR.

Mitigation should focus on promptly updating the InsydeH2O firmware to the fixed versions listed (05.29.50 or later for kernel 5.2, 05.38.50 or later for kernel 5.3, etc.). Organizations should coordinate with device vendors and manufacturers to obtain and deploy these firmware updates as soon as they become available. Until patches are applied, organizations should enforce strict access controls to limit local administrative privileges and monitor for suspicious activities indicative of privilege escalation or firmware tampering attempts. Implementing endpoint detection and response (EDR) solutions capable of detecting anomalous firmware or bootloader behavior can help identify exploitation attempts. Additionally, organizations should verify Secure Boot status regularly and consider hardware-based attestation mechanisms to detect unauthorized firmware changes. For high-security environments, consider isolating critical systems and limiting physical access to prevent local exploitation. Finally, maintain an inventory of devices using InsydeH2O firmware to prioritize patching and risk management efforts effectively.