CVE-2024-45777 is a vulnerability identified in grub2, the widely used bootloader for Linux systems. The flaw arises from an out-of-bounds write condition during the calculation of the translation buffer when grub2 reads language .mo files in the function grub_gettext_getstr_from_position(). Specifically, the buffer size calculation can overflow, allowing an attacker to write beyond the allocated memory bounds. This memory corruption can overwrite sensitive heap data structures within grub2, which is critical because grub2 operates early in the boot process and is responsible for enforcing secure boot protections. By corrupting heap data, an attacker may bypass secure boot mechanisms, undermining the system's trust chain and potentially allowing unauthorized code execution during boot. The vulnerability requires the attacker to have local access with high privileges (PR:H) and does not require user interaction (UI:N). The attack vector is local (AV:L), meaning remote exploitation is not feasible without prior access. The CVSS v3.1 base score is 6.7, indicating a medium severity level with high impact on confidentiality, integrity, and availability if exploited. No public exploits are currently known, and no patches are linked yet, but the issue is recognized and published by authoritative sources including Red Hat and CISA. This vulnerability is particularly relevant for environments that rely on grub2 with secure boot enabled, as the bypass could lead to persistent, stealthy compromise at the bootloader level.

For European organizations, the impact of CVE-2024-45777 can be significant, especially in sectors where secure boot is mandated to ensure system integrity, such as government, finance, healthcare, and critical infrastructure. Successful exploitation could allow attackers with local elevated privileges to bypass secure boot protections, potentially enabling persistent malware that loads before the operating system, evading traditional detection mechanisms. This undermines the trustworthiness of the boot process and can lead to full system compromise, data breaches, or disruption of critical services. Organizations using grub2 on Linux servers, workstations, or embedded devices are at risk, particularly those that enforce secure boot as part of their security posture. Although exploitation requires local access with high privileges, insider threats or attackers who have already gained partial access could leverage this vulnerability to escalate control and maintain persistence. The absence of known exploits in the wild currently reduces immediate risk but does not eliminate the threat, especially as attackers often develop exploits after vulnerability disclosure. The medium CVSS score reflects the balance between the high impact and the requirement for local privileged access, but the potential to bypass secure boot elevates the criticality of timely mitigation.

To mitigate CVE-2024-45777, European organizations should: 1) Monitor vendor advisories closely and apply patches or updates to grub2 as soon as they become available, as no official patch links are currently provided. 2) Restrict local access to systems running grub2, enforcing strict privilege separation and limiting administrative accounts to reduce the risk of privilege escalation. 3) Harden boot configurations by verifying the integrity of grub2 files and restricting modification permissions on language .mo files and grub configuration directories to prevent tampering. 4) Employ host-based intrusion detection systems (HIDS) to monitor for unusual changes in bootloader files or unauthorized access attempts. 5) Use secure boot policies combined with hardware root of trust mechanisms to detect and prevent unauthorized bootloader modifications. 6) Conduct regular audits of user privileges and system access logs to detect potential insider threats or lateral movement that could lead to exploitation. 7) Prepare incident response plans that include bootloader compromise scenarios to enable rapid containment and recovery. These steps go beyond generic advice by focusing on controlling local access, protecting grub2 components, and preparing for boot-level compromise.