CVE-2024-52878 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, which handles UEFI variable services. The function VariableServicesSetVariable() is called by several interfaces including gRT_->SetVariable(), SmmSetSensitiveVariable(), and SmmInternalSetVariable() from the System Management Mode (SMM). Within this function, string operations such as StrSize(), StrLen(), and StrCmp() are used to determine the size, length, and comparison of variable names. Improper handling of these string operations leads to a buffer over-read condition, classified under CWE-126. This buffer over-read can allow an attacker to read memory beyond the intended buffer boundaries, potentially exposing sensitive information stored in firmware variables. The vulnerability can be exploited remotely without authentication or user interaction, as indicated by the CVSS vector (AV:N/AC:L/PR:N/UI:N). While the vulnerability does not impact integrity or availability directly, the confidentiality impact is high, as attackers may gain access to sensitive firmware data. No known exploits are currently reported in the wild, and no official patches have been linked yet. The vulnerability affects the firmware layer, which is critical for system boot and security, making it a significant risk if exploited.

For European organizations, this vulnerability poses a substantial risk due to the widespread use of InsydeH2O firmware in laptops, desktops, and embedded systems from various manufacturers. Exposure of sensitive firmware variables could lead to leakage of cryptographic keys, secure boot parameters, or other confidential information, undermining device security and trustworthiness. This could facilitate further attacks such as firmware rootkits or persistent malware implants. Critical sectors including finance, government, healthcare, and industrial control systems in Europe could be particularly impacted, as these sectors rely heavily on endpoint security and firmware integrity. The vulnerability’s remote exploitability without user interaction increases the risk of large-scale automated attacks or targeted espionage campaigns. Additionally, the lack of patches at the time of disclosure means organizations must act quickly to mitigate risk. The firmware-level nature of the vulnerability also complicates detection and remediation, potentially requiring coordinated firmware updates from device vendors.

European organizations should immediately identify and inventory devices using InsydeH2O firmware versions affected by this vulnerability. Engage with hardware vendors and OEMs to obtain and deploy firmware updates as soon as they become available. In the interim, implement network-level protections such as strict firewall rules to limit exposure of vulnerable devices to untrusted networks. Employ endpoint detection and response (EDR) solutions capable of monitoring unusual firmware or system management mode activity. Consider disabling or restricting access to UEFI variable modification interfaces where feasible, especially in managed environments. Conduct thorough firmware integrity checks and enable secure boot features to prevent unauthorized firmware modifications. Additionally, organizations should enhance monitoring for indicators of compromise related to firmware attacks and educate IT staff on the risks associated with firmware vulnerabilities. Regularly review and update asset management databases to ensure all firmware versions are tracked and patched promptly.