CVE-2024-0775 is a use-after-free vulnerability identified in the Linux kernel's ext4 filesystem code, specifically within the __ext4_remount function located in fs/ext4/super.c. The flaw arises during the remounting process of ext4 filesystems when the kernel attempts to free old quota file names before a potential failure occurs. Improper handling leads to a use-after-free condition, which can be exploited by a local user with high privileges to cause an information leak. This vulnerability affects the confidentiality, integrity, and availability of the system by potentially exposing sensitive kernel memory contents and destabilizing filesystem operations. The CVSS 3.1 score of 6.7 reflects a medium severity, with attack vector local, low attack complexity, high privileges required, no user interaction, and impacts on confidentiality, integrity, and availability. No public exploits are known at this time, but the vulnerability presents a risk in environments where local users have elevated access. The flaw is particularly relevant for Linux systems using ext4, which is a widely deployed filesystem in servers and enterprise environments. The vulnerability was published on January 22, 2024, and assigned by Red Hat, indicating that patches or mitigations may be available from major Linux distributions. The vulnerability does not require user interaction but does require privileged local access, limiting remote exploitation but still posing a risk in multi-user or shared environments.

For European organizations, the impact of CVE-2024-0775 can be significant, especially in sectors relying heavily on Linux servers with ext4 filesystems, such as finance, telecommunications, government, and critical infrastructure. The vulnerability allows a local privileged attacker to leak sensitive information from kernel memory, potentially exposing confidential data or cryptographic material. This can lead to further privilege escalation or targeted attacks. Additionally, the use-after-free condition could cause system instability or crashes, impacting availability of critical services. Organizations with multi-tenant environments or shared hosting are at higher risk due to the possibility of malicious insiders or compromised accounts exploiting this flaw. The medium severity rating suggests that while the vulnerability is not trivially exploitable remotely, the consequences of exploitation could disrupt operations and compromise sensitive information. Given the widespread use of Linux and ext4 in European data centers and cloud environments, the threat is relevant across multiple industries.

To mitigate CVE-2024-0775, European organizations should: 1) Apply security patches and kernel updates provided by Linux distribution vendors promptly to ensure the vulnerability is remediated. 2) Restrict local privileged access strictly, enforcing the principle of least privilege to minimize the number of users who can exploit this flaw. 3) Monitor system logs and audit filesystem remount operations for unusual activity that could indicate exploitation attempts. 4) Employ kernel hardening techniques such as SELinux or AppArmor to limit the impact of potential exploits. 5) In environments where patching is delayed, consider isolating critical systems or using virtualization/containerization to reduce attack surface. 6) Conduct regular security assessments and penetration tests focusing on local privilege escalation vectors. 7) Educate system administrators about this vulnerability and the importance of controlling local access and promptly applying updates.