CVE-2024-36955 is a high-severity vulnerability identified in the Linux kernel, specifically within the ALSA (Advanced Linux Sound Architecture) subsystem's hda driver component related to Intel SoundWire ACPI (intel-sdw-acpi). The issue stems from improper management of firmware node references when using the function device_get_named_child_node(). According to the Linux kernel documentation, callers of this function must invoke fwnode_handle_put() to release the reference to the firmware node pointer returned. Failure to do so results in a reference leak. This vulnerability was addressed by adding the missing fwnode_handle_put() call to prevent the leaked reference. The CVSS v3.1 score is 7.7 (high), with vector AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H, indicating that the attack requires local access (AV:L), low complexity (AC:L), no privileges (PR:N), no user interaction (UI:N), unchanged scope (S:U), high confidentiality impact (C:H), no integrity impact (I:N), and high availability impact (A:H). The vulnerability is classified under CWE-200 (Exposure of Sensitive Information). Although no known exploits are currently reported in the wild, the vulnerability could allow a local attacker to cause a denial of service (system crash) and potentially gain unauthorized access to sensitive information due to leaked references. The affected versions are specific Linux kernel commits identified by their hashes. This flaw is technical and subtle, involving kernel memory and resource management, and requires local access to exploit, but no privileges or user interaction, making it a significant risk in multi-user or shared environments.

For European organizations, the impact of CVE-2024-36955 is primarily on systems running vulnerable Linux kernel versions with ALSA sound drivers enabled, especially those using Intel SoundWire ACPI hardware. The vulnerability can lead to denial of service conditions, causing system instability or crashes, which could disrupt critical services, especially in environments relying on Linux servers, workstations, or embedded devices. The high confidentiality impact suggests potential exposure of sensitive kernel memory or data, which could be leveraged for further attacks or information leaks. Organizations with multi-user systems, shared hosting, or environments where untrusted local users have access are at greater risk. This includes academic institutions, research labs, cloud providers, and enterprises using Linux desktops or servers. The absence of required privileges for exploitation increases the threat level. Disruptions could affect operational continuity, data confidentiality, and system reliability, impacting sectors such as finance, healthcare, manufacturing, and government services across Europe.

To mitigate CVE-2024-36955, European organizations should: 1) Immediately apply the official Linux kernel patches that address the missing fwnode_handle_put() call in the intel-sdw-acpi ALSA driver. Monitor kernel update releases from trusted Linux distributions and vendors. 2) For systems where immediate patching is not feasible, consider disabling or unloading the ALSA hda Intel SoundWire ACPI driver if audio functionality is not critical, to reduce attack surface. 3) Implement strict local access controls and user privilege restrictions to limit untrusted user access to vulnerable systems. 4) Employ kernel hardening techniques such as SELinux or AppArmor policies to restrict access to kernel interfaces and device nodes related to sound drivers. 5) Monitor system logs and kernel messages for unusual crashes or anomalies that could indicate exploitation attempts. 6) Conduct regular vulnerability assessments and penetration testing focusing on local privilege escalation and denial of service vectors. 7) Educate system administrators about the importance of timely kernel updates and the risks of local vulnerabilities. These steps go beyond generic advice by focusing on driver-specific mitigations, access controls, and monitoring tailored to this vulnerability's characteristics.