CVE-2025-4382 is a vulnerability affecting systems that use LUKS (Linux Unified Key Setup) encrypted disks combined with GRUB bootloader configured for TPM (Trusted Platform Module)-based automatic disk decryption. In this setup, GRUB retrieves the disk decryption key from the TPM and loads it into system memory to decrypt the disk automatically during boot. The vulnerability arises when an attacker with physical access corrupts the filesystem superblock on the encrypted disk. This corruption causes GRUB to fail to locate a valid filesystem and enter rescue mode. Critically, at this point, the disk has already been decrypted, and the decryption key remains resident in system memory. Consequently, an attacker can access the unencrypted data without any further authentication, compromising data confidentiality. Additionally, the attacker’s ability to induce this state by corrupting the filesystem superblock also raises concerns about data integrity, as the filesystem is effectively damaged and may be manipulated or rendered unusable. This vulnerability specifically impacts Red Hat Enterprise Linux 10 systems configured with TPM-based auto-decryption via GRUB. The CVSS v3.1 score of 5.9 (medium severity) reflects the vulnerability’s requirement for physical access and limited privileges (PR:L), but also its high impact on confidentiality and integrity. No known exploits are currently reported in the wild.

For European organizations, this vulnerability poses a significant risk to the confidentiality and integrity of sensitive data stored on LUKS-encrypted disks with TPM-based auto-decryption. Organizations relying on this configuration for secure disk encryption—such as government agencies, financial institutions, healthcare providers, and enterprises handling regulated data—may face unauthorized data disclosure if an attacker gains physical access to affected systems. The attack does not require user interaction or complex privilege escalation, only physical access and the ability to corrupt the filesystem superblock, which could be achieved via direct hardware manipulation or malicious peripherals. This risk is heightened in environments with less stringent physical security controls, such as remote offices or shared facilities. Additionally, the integrity of data is at risk since filesystem corruption can disrupt normal operations and potentially lead to data loss or system downtime. The vulnerability undermines the trust in TPM-based auto-decryption mechanisms, which are often deployed to streamline secure boot processes without sacrificing security. European organizations must consider the implications for compliance with data protection regulations like GDPR, as unauthorized data access could lead to regulatory penalties and reputational damage.

To mitigate this vulnerability, European organizations should: 1) Avoid relying solely on TPM-based automatic disk decryption in environments where physical security cannot be guaranteed. 2) Implement additional authentication mechanisms at boot time, such as requiring a PIN or passphrase in addition to TPM key retrieval, to prevent unauthorized access if the system enters rescue mode. 3) Regularly monitor and verify filesystem integrity using tools like fsck and implement filesystem-level protections to detect and prevent superblock corruption. 4) Harden physical security controls to restrict unauthorized physical access to critical systems, including secure server rooms, locked hardware cabinets, and surveillance. 5) Apply all available patches and updates from Red Hat as soon as they are released to address this vulnerability. 6) Consider disabling TPM-based auto-decryption where feasible and use manual decryption methods that require user authentication at boot. 7) Maintain regular backups of critical data to enable recovery in case of filesystem corruption or data loss. 8) Conduct security awareness training for staff to recognize and report suspicious physical access attempts.