CVE-2024-52877 is a high-severity vulnerability identified in the InsydeH2O UEFI firmware, specifically affecting multiple kernel versions prior to 05.29.50 through 05.70.50. The vulnerability resides in the VariableRuntimeDxe driver within the callback function SmmCreateVariableLockList(), which calls CreateVariableLockListInSmm(). In this function, the StrSize() method is used to determine the size of a variable name. However, improper handling leads to a buffer over-read condition (CWE-126). This means that the function reads memory beyond the intended buffer boundary, potentially exposing sensitive data stored adjacent to the buffer. The vulnerability does not require any privileges or user interaction to exploit (CVSS vector: AV:N/AC:L/PR:N/UI:N), indicating that a remote attacker could trigger this flaw without authentication. The impact is primarily on confidentiality, as the attacker could read sensitive information from memory, but there is no direct impact on integrity or availability. Although no known exploits are currently reported in the wild, the vulnerability's nature and ease of exploitation make it a significant risk. The absence of patch links suggests that remediation may require firmware updates from device manufacturers or vendors. Given that InsydeH2O firmware is widely used in laptops, desktops, and embedded devices from various OEMs, this vulnerability could affect a broad range of systems that rely on these firmware versions. The buffer over-read could be leveraged to leak sensitive firmware or system information, potentially aiding further attacks or privilege escalation.

For European organizations, the confidentiality breach posed by this vulnerability is critical, especially in sectors handling sensitive data such as finance, healthcare, government, and critical infrastructure. Exposure of firmware-level information could facilitate advanced persistent threats (APTs) or targeted espionage campaigns. Since InsydeH2O firmware is common in many commercial devices sold in Europe, organizations may have a large attack surface. The vulnerability's ability to be exploited without authentication or user interaction increases the risk of automated or remote attacks. While the vulnerability does not directly impact system availability or integrity, the leaked information could be used to craft more damaging exploits or bypass security controls. This is particularly concerning for organizations with strict data protection regulations like GDPR, as unauthorized data exposure could lead to compliance violations and reputational damage. Furthermore, the lack of immediate patches means organizations must proactively assess their device inventory and firmware versions to identify vulnerable systems and coordinate with hardware vendors for updates.

1. Inventory and Identification: Conduct a thorough inventory of all devices running InsydeH2O firmware, identifying versions prior to the fixed releases (05.29.50, 05.38.50, 05.46.50, 05.54.50, 05.61.50, 05.70.50). 2. Firmware Updates: Engage with hardware vendors and OEMs to obtain and deploy firmware updates that address this vulnerability as soon as they become available. 3. Network Segmentation: Isolate vulnerable devices from critical network segments to reduce exposure to remote exploitation. 4. Monitoring and Detection: Implement enhanced monitoring for unusual firmware or system behavior that could indicate exploitation attempts, including memory access anomalies. 5. Access Controls: Restrict remote management interfaces and disable unnecessary services that could be leveraged to trigger the vulnerability. 6. Incident Response Preparedness: Prepare incident response plans specifically addressing firmware-level compromises and data leakage scenarios. 7. Vendor Communication: Maintain active communication channels with Insyde and OEMs for timely security advisories and patches. 8. User Awareness: Educate IT staff about the risks associated with firmware vulnerabilities and the importance of timely patching.