CVE-2025-0624 is a vulnerability identified in grub2, the widely used bootloader for Linux systems, specifically during the network boot process. When grub attempts to locate its configuration file over the network, it copies data from an environment variable controlled by the user into an internal buffer using the grub_strcpy() function. The vulnerability stems from grub failing to properly consider the length of this environment variable when allocating the buffer, resulting in an out-of-bounds write. This memory corruption can be leveraged by an attacker positioned on the same network segment to execute arbitrary code remotely. The flaw effectively allows bypassing secure boot protections, which are designed to ensure only trusted code runs during system startup. The CVSS 3.1 score of 7.6 reflects a high severity, with attack vector classified as adjacent network (AV:A), requiring high privileges (PR:H), and no user interaction (UI:N). The scope is changed (S:C), indicating that exploitation affects components beyond the vulnerable component itself. Confidentiality, integrity, and availability impacts are all high, meaning an attacker can fully compromise the affected system. Although no known exploits are currently reported in the wild, the vulnerability poses a significant risk to systems relying on grub2 network boot, especially in environments where secure boot is critical for system integrity. The vulnerability was reserved in January 2025 and published in February 2025, with enrichment from CISA and Red Hat assigner information. No patches or exploit indicators are currently listed, emphasizing the need for proactive mitigation.

For European organizations, the impact of CVE-2025-0624 can be severe, particularly for enterprises and data centers that utilize network booting with grub2. Successful exploitation allows attackers on the same network segment to execute arbitrary code during the boot process, potentially gaining persistent, low-level control over systems. This undermines secure boot protections, which are fundamental for preventing unauthorized code execution at startup. Critical infrastructure sectors such as finance, healthcare, telecommunications, and government agencies that rely on secure and trusted boot processes are at heightened risk. The breach could lead to data theft, system manipulation, ransomware deployment, or disruption of services. Additionally, the vulnerability could facilitate lateral movement within internal networks, escalating the threat to broader organizational assets. Given the high privileges required, the threat actor profile is likely to be an insider or a sophisticated attacker with network access. The absence of known exploits currently provides a window for mitigation, but the potential for rapid weaponization exists.

European organizations should immediately audit their use of grub2, particularly focusing on systems that employ network booting. Although no patches are currently available, organizations should monitor vendor advisories closely and apply updates promptly once released. Network segmentation should be enforced to limit access to the network segments used for boot configuration retrieval, restricting it to trusted devices only. Implement strict access controls and monitoring on DHCP, TFTP, and PXE services involved in network boot processes. Employ network intrusion detection systems (NIDS) to detect anomalous activities on boot-related network segments. Consider disabling network boot where it is not essential or replacing it with more secure alternatives. Review and harden secure boot configurations and verify bootloader integrity regularly. For critical systems, implement multi-factor authentication and physical security controls to reduce the risk of privilege escalation. Finally, conduct penetration testing and vulnerability assessments targeting boot processes to identify potential exploitation paths.