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 caused by improper calculation of the translation buffer when grub2 reads language .mo files in the function grub_gettext_getstr_from_position(). This buffer overflow can overwrite sensitive heap data within grub2's memory space. Since grub2 operates early in the boot process and is responsible for loading the operating system securely, corrupting its heap data can allow an attacker to circumvent secure boot protections. Secure boot is a critical security feature designed to ensure that only trusted software is loaded during system startup, preventing rootkits and bootkits. The vulnerability requires an attacker to have local access with high privileges (as indicated by the CVSS vector AV:L/PR:H), and no user interaction is needed. The flaw impacts confidentiality, integrity, and availability of the boot process, with a CVSS score of 6.7 (medium severity). No public exploits are known at this time, but the potential for secure boot bypass makes this a significant concern. The vulnerability affects grub2 versions prior to the patch, although specific affected versions were not detailed. The issue was reserved in September 2024 and published in February 2025, with enrichment from CISA indicating recognition by US cybersecurity authorities.

For European organizations, this vulnerability poses a risk to the integrity of the boot process on Linux systems using grub2, especially those relying on secure boot to protect against low-level malware and firmware attacks. Successful exploitation could allow attackers to bypass secure boot, leading to persistent compromise, stealthy rootkits, or unauthorized system modifications. This could impact critical infrastructure, government systems, and enterprises with stringent security requirements. Confidentiality could be compromised if attackers gain control over the boot process to load malicious code that intercepts data. Integrity is directly affected as the bootloader's memory can be corrupted. Availability could also be impacted if the system becomes unstable or fails to boot properly. The requirement for local high-privilege access limits the attack surface but does not eliminate risk, especially in environments where insider threats or lateral movement are possible. European organizations with extensive Linux deployments in sectors like finance, energy, telecommunications, and public administration should prioritize addressing this vulnerability.

1. Apply official patches from grub2 maintainers as soon as they are released to address the out-of-bounds write vulnerability. 2. Restrict local privileged access to trusted administrators only, minimizing the risk of exploitation by malicious insiders or compromised accounts. 3. Implement strict access controls and monitoring on systems with grub2 to detect unauthorized attempts to modify or replace language .mo files or grub2 binaries. 4. Employ secure boot validation and integrity checking tools to monitor bootloader integrity and detect anomalies early. 5. Use hardware-based security features such as TPM (Trusted Platform Module) to strengthen secure boot enforcement. 6. Conduct regular audits of boot configurations and update security policies to include bootloader protection. 7. Educate system administrators about the risks of local privilege escalation and the importance of secure boot protections. 8. Consider isolating critical systems or using virtualization/containerization to limit the impact of potential exploitation.