CVE-2024-45780 is a vulnerability identified in grub2, a widely used bootloader in Linux-based systems. The flaw arises during the processing of tar files, where grub2 allocates an internal buffer to store the file name. However, it fails to properly validate the allocation size against integer overflow conditions. By crafting a specially designed tar file, an attacker can cause the allocation length to overflow, resulting in a heap out-of-bounds write. This memory corruption can be leveraged to manipulate the bootloader's behavior, potentially allowing an attacker to bypass secure boot protections. Secure boot is a critical security feature that ensures only trusted software is loaded during system startup. Circumventing this mechanism can lead to unauthorized code execution at a very early stage of the boot process, undermining system integrity and trustworthiness. The vulnerability requires local access with high privileges (as indicated by the CVSS vector AV:L/PR:H), meaning an attacker must already have significant control over the system to exploit it. No user interaction is needed, and the scope is unchanged, affecting only the vulnerable component. Although no known exploits are currently reported in the wild, the potential impact on confidentiality, integrity, and availability is high due to the ability to subvert secure boot. The CVSS score of 6.7 classifies this as a medium severity issue. The vulnerability affects all versions of grub2 prior to the patch, and while no patch links are currently provided, vendors are expected to release fixes promptly. Organizations using grub2, especially in environments where secure boot is enforced, should prioritize remediation once patches become available.

For European organizations, this vulnerability poses a significant risk particularly to enterprises and critical infrastructure sectors that rely on Linux systems with grub2 as the bootloader. Successful exploitation can allow attackers to bypass secure boot protections, potentially enabling persistent and stealthy malware infections that load before the operating system. This undermines system integrity and can lead to full system compromise, data breaches, or disruption of services. Confidentiality is at risk as attackers could execute arbitrary code at boot time, integrity is compromised by the ability to alter boot processes, and availability may be affected if systems become unstable or unusable. The requirement for local privileged access limits remote exploitation but insider threats or attackers who have already gained elevated privileges could leverage this flaw to escalate control. The absence of known exploits in the wild currently reduces immediate risk, but the vulnerability should be treated seriously given the critical role of secure boot in system security.

European organizations should implement the following specific mitigations: 1) Monitor vendor advisories closely and apply patches for grub2 as soon as they are released to address this integer overflow and out-of-bounds write issue. 2) Restrict and monitor privileged local access to systems using grub2 to reduce the risk of exploitation by insiders or attackers with elevated privileges. 3) Employ integrity verification tools to detect unauthorized changes to bootloader components. 4) Use hardware-based secure boot enforcement and ensure firmware is up to date to add layers of protection. 5) Conduct regular security audits and penetration tests focusing on bootloader and early boot process security. 6) Implement strict access controls and logging on systems that handle tar files or perform bootloader updates to detect suspicious activity. 7) Educate system administrators about the risks of local privilege escalation vulnerabilities and the importance of secure boot integrity.