CVE-2024-49925 is a vulnerability identified in the Linux kernel, specifically related to the framebuffer device (fbdev) subsystem's efifb driver. The issue arises from improper handling of sysfs groups registration and cleanup within the driver core. The vulnerability involves a use-after-free (UAF) race condition during the unregistering process, where sysctl attributes remain accessible after the associated info structure has been freed. This can lead to potential memory corruption or kernel instability. The fix involves leveraging the driver core's ability to register and clean up sysfs groups properly, simplifying error handling and preventing the race condition. The vulnerability affects certain Linux kernel versions identified by specific commit hashes, and no known exploits are currently reported in the wild. The vulnerability was published on October 21, 2024, and while no CVSS score is assigned, the technical details indicate a kernel-level memory management flaw that could be exploited under certain conditions.

For European organizations, this vulnerability poses a risk primarily to systems running affected Linux kernel versions with the efifb driver enabled, which is common in servers, workstations, and embedded devices using EFI framebuffer for display output. Exploitation could lead to kernel crashes, denial of service, or potentially privilege escalation if an attacker can trigger the use-after-free condition. This could disrupt critical infrastructure, cloud services, and enterprise IT environments relying on Linux-based systems. The impact is heightened in sectors with high Linux adoption such as telecommunications, finance, and government institutions. Although no active exploits are known, the vulnerability's presence in the kernel means that unpatched systems remain at risk, especially in environments where local or remote code execution is feasible. The vulnerability could also be leveraged as part of a multi-stage attack chain, increasing the threat to confidentiality, integrity, and availability of affected systems.

European organizations should prioritize updating their Linux kernel to the patched versions that address CVE-2024-49925 as soon as they become available. System administrators should audit their environments to identify systems using the efifb driver and verify kernel versions. Employing kernel live patching solutions can reduce downtime during remediation. Additionally, organizations should implement strict access controls to limit unprivileged users from triggering kernel-level operations that could exploit this vulnerability. Monitoring kernel logs for unusual sysfs or sysctl activity may help detect exploitation attempts. For critical infrastructure, consider isolating vulnerable systems or using virtualization/containerization to limit potential damage. Regularly review and update security policies to include rapid deployment of kernel patches and maintain an inventory of Linux kernel versions in use.