CVE-2025-0622 is a use-after-free vulnerability identified in the GRUB2 bootloader, specifically related to the handling of hooks created by loaded modules. The vulnerability arises because, in certain scenarios, hooks registered by modules are not properly removed when the corresponding module is unloaded. This results in GRUB2 potentially invoking hooks that reference freed memory, leading to a use-after-free condition. Exploiting this flaw could allow an attacker to execute arbitrary code during the boot process. Since GRUB2 is a critical component responsible for loading the operating system, successful exploitation can enable bypassing secure boot protections, undermining the system's trusted boot chain. The vulnerability has a CVSS 3.1 base score of 6.4, indicating a medium severity level. The vector details specify that exploitation requires local access (AV:L), high attack complexity (AC:H), high privileges (PR:H), no user interaction (UI:N), and impacts confidentiality, integrity, and availability (C:H/I:H/A:H). No known exploits are currently reported in the wild, and no patches or vendor-specific product details are provided yet. The flaw is significant because it targets the bootloader, a foundational security component, and could facilitate persistent, stealthy compromise by attackers with local privileged access.

For European organizations, the impact of CVE-2025-0622 can be substantial, especially for those relying on Linux-based systems that use GRUB2 as the bootloader. Successful exploitation could allow attackers to bypass secure boot mechanisms, which are designed to ensure that only trusted software is loaded during system startup. This could lead to persistent malware infections, rootkits, or other advanced threats that are difficult to detect and remove. Critical infrastructure sectors, government agencies, financial institutions, and enterprises with high security requirements could face increased risks of system compromise, data breaches, and operational disruptions. The requirement for local high-privilege access limits remote exploitation but does not eliminate risk, as insider threats or attackers who have already gained some level of access could leverage this vulnerability to escalate privileges and maintain persistence. The compromise of secure boot also undermines hardware-based security assurances, potentially affecting compliance with European cybersecurity regulations such as the NIS Directive and GDPR if sensitive data or critical services are impacted.

To mitigate CVE-2025-0622, European organizations should take the following specific actions: 1) Monitor vendor advisories closely for patches or updates to GRUB2 addressing this vulnerability and apply them promptly once available. 2) Restrict and monitor local privileged access to systems using GRUB2, employing strict access controls and auditing to detect unauthorized attempts to load or unload modules. 3) Implement robust endpoint security solutions capable of detecting anomalous behavior during boot or module manipulation. 4) Use hardware-based security features such as TPM and secure boot policies to enforce boot integrity, and verify their configurations regularly. 5) Conduct regular security assessments and penetration tests focusing on bootloader security to identify potential exploitation paths. 6) Educate system administrators about the risks of loading untrusted modules and the importance of maintaining secure boot configurations. 7) Where feasible, consider using alternative bootloaders or hardened GRUB2 builds that have mitigations against use-after-free vulnerabilities. These measures go beyond generic patching advice by emphasizing access control, monitoring, and configuration hardening tailored to the nature of this vulnerability.