CVE-2024-53174 is a high-severity vulnerability in the Linux kernel related to the SUNRPC subsystem, specifically involving a use-after-free condition in the cache management code. The vulnerability arises because the function c_show was called with Read-Copy-Update (RCU) protection, which only guarantees that the cache pointer (cp) will not be freed during the operation. However, this protection does not prevent the reference count of cp from dropping to zero, which can lead to a use-after-free scenario when cache_get is subsequently called. This is a classic reference count use-after-free vulnerability (CWE-416), where the reference count can be decremented to zero and the object freed, but a stale pointer is still used afterward. The kernel log snippet included in the description shows a refcount warning triggered during execution, indicating the presence of this flaw. The fix involves replacing cache_get with cache_get_rcu to ensure the cache entry remains active and its reference count is properly maintained during the operation. The vulnerability affects Linux kernel versions prior to the patch and is exploitable locally with low attack complexity and low privileges required (PR:L), without user interaction (UI:N). The CVSS v3.1 base score is 7.8, reflecting high impact on confidentiality, integrity, and availability due to potential arbitrary code execution or denial of service. No known exploits are currently reported in the wild, but the vulnerability's nature and kernel-level impact make it a significant risk once weaponized. The affected versions are identified by a specific commit hash, indicating the vulnerability is in recent or development kernel versions (6.12.0-rc3+).

For European organizations, this vulnerability poses a significant risk because Linux is widely deployed across servers, cloud infrastructure, embedded devices, and critical systems. Exploitation could allow local attackers or compromised low-privilege users to escalate privileges, execute arbitrary code in kernel context, or cause denial of service by crashing the system. This could lead to data breaches, service outages, and disruption of business operations. Organizations relying on Linux-based infrastructure for web hosting, cloud services, telecommunications, or industrial control systems could be particularly affected. The high impact on confidentiality, integrity, and availability means sensitive data could be exposed or corrupted, and critical services could be interrupted. The lack of known exploits currently provides a window for proactive patching, but the vulnerability's presence in the kernel means that once exploits emerge, the impact could be widespread and severe. Additionally, the vulnerability could be leveraged in multi-stage attacks targeting European critical infrastructure or enterprises, especially those with remote access or multi-user environments where local privilege escalation is a common attack vector.

European organizations should immediately assess their Linux kernel versions and prioritize patching to the latest stable kernel releases that include the fix for CVE-2024-53174. Since the vulnerability requires local access, organizations should also strengthen access controls to limit untrusted user logins and employ strict privilege separation. Implement kernel live patching where possible to reduce downtime during patch deployment. Conduct thorough audits of systems running vulnerable kernels, especially those exposed to multiple users or untrusted code execution. Employ runtime security tools that can detect anomalous kernel behavior or refcount misuse. For environments where immediate patching is not feasible, consider disabling or restricting SUNRPC services if not required, as this subsystem is directly involved. Maintain robust monitoring and alerting for kernel crashes or refcount warnings in system logs, which could indicate exploitation attempts. Finally, ensure that endpoint security solutions are updated to detect potential exploit attempts targeting this vulnerability.