CVE-2024-45781 is a vulnerability identified in grub2, the widely used bootloader for Unix-like systems. The issue occurs during the reading of symbolic link names from UFS (Unix File System) filesystems. grub2 fails to properly validate the length of the string input representing the symbolic link's name, which leads to a heap out-of-bounds write. This memory corruption can compromise data integrity within the bootloader's runtime environment. More critically, this flaw can be leveraged by an attacker to circumvent secure boot protections, which are designed to ensure that only trusted software is loaded during system startup. 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, reflecting medium severity with high impact on confidentiality, integrity, and availability. No public exploits are currently known, and no patches have been linked yet. The vulnerability was reserved in September 2024 and published in February 2025, indicating recent discovery and disclosure. grub2’s role in the boot process and the ability to bypass secure boot protections make this a significant threat to system security and trustworthiness.

For European organizations, this vulnerability poses a risk primarily to systems that use grub2 as their bootloader and mount UFS filesystems, which are less common but still present in certain legacy or specialized environments. The ability to perform a heap out-of-bounds write can lead to corruption of bootloader data structures, potentially allowing attackers to bypass secure boot mechanisms. This undermines the integrity of the system startup process, enabling the execution of unauthorized code early in the boot sequence. Such compromise can lead to persistent malware infections, data breaches, and disruption of critical services. Organizations in sectors with stringent security requirements—such as finance, government, healthcare, and critical infrastructure—may face elevated risks. The requirement for local high-privilege access limits the threat to insiders or attackers who have already gained elevated access, but the impact of exploitation remains severe. The absence of known exploits reduces immediate risk but does not eliminate the threat, especially as attackers may develop exploits post-disclosure.

1. Monitor vendor advisories closely and apply patches or updates for grub2 as soon as they become available. 2. Restrict local administrative access to trusted personnel only, employing strict access controls and monitoring to prevent unauthorized privilege escalation. 3. Implement robust host-based intrusion detection and prevention systems to detect anomalous behavior indicative of exploitation attempts. 4. Enforce secure boot policies and verify bootloader integrity regularly using trusted platform modules (TPM) or equivalent hardware security features. 5. Where feasible, avoid using UFS filesystems or isolate systems that require UFS to minimize exposure. 6. Conduct regular security audits and penetration testing focusing on boot process security and privilege escalation vectors. 7. Employ multi-factor authentication and session management controls to reduce the risk of unauthorized local access. 8. Maintain comprehensive logging of bootloader and system events to facilitate forensic analysis if an incident occurs.