CVE-2021-47329 is a medium severity vulnerability identified in the Linux kernel's megaraid_sas SCSI driver. The issue arises during the PCI device probe process, specifically when the function megasas_start_aen() fails after scsi_add_host() has been called. In this failure scenario, the driver does not properly release all allocated resources, resulting in a resource leak. This leak can lead to exhaustion of kernel resources, potentially causing a denial of service (DoS) condition by impairing the availability of the affected system. The vulnerability is classified under CWE-400 (Uncontrolled Resource Consumption), indicating that the system's resources can be depleted due to improper cleanup. The CVSS v3.1 base score is 6.2, reflecting a medium severity with the vector AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H, meaning the attack requires local access, low attack complexity, no privileges or user interaction, and impacts availability only. No known exploits are reported in the wild as of the publication date. The vulnerability affects Linux kernel versions identified by the given commit hashes, and a patch has been implemented to ensure all allocated resources are cleaned up properly during probe failure, mitigating the risk of resource leaks.

For European organizations, the impact of CVE-2021-47329 primarily concerns systems running Linux kernels with the megaraid_sas driver, commonly found in servers and storage arrays that use MegaRAID SAS controllers. The vulnerability could be exploited by an attacker with local access to cause resource exhaustion, leading to denial of service. This could disrupt critical services, especially in data centers, cloud infrastructure, and enterprise environments relying on Linux-based storage solutions. Although the attack requires local access, insider threats or compromised user accounts could leverage this vulnerability to degrade system availability. The absence of confidentiality or integrity impact limits the scope to availability, but given the importance of storage controllers in enterprise environments, service outages could have significant operational and financial consequences. European organizations with high reliance on Linux-based storage infrastructure, such as financial institutions, telecommunications providers, and public sector entities, could face service disruptions if this vulnerability is exploited.

To mitigate CVE-2021-47329, organizations should: 1) Apply the latest Linux kernel updates that include the patch fixing the resource leak in the megaraid_sas driver. 2) Audit and monitor systems using MegaRAID SAS controllers to ensure they are running patched kernel versions. 3) Restrict local access to critical Linux servers to trusted personnel only, minimizing the risk of exploitation by untrusted users. 4) Implement robust access controls and user activity monitoring to detect unusual behavior indicative of attempts to exploit local vulnerabilities. 5) For environments where patching is delayed, consider temporary workarounds such as disabling the megaraid_sas driver if it is not essential, or isolating affected systems to limit potential impact. 6) Incorporate resource usage monitoring to detect abnormal resource consumption patterns that may indicate exploitation attempts. These steps go beyond generic advice by focusing on the specific driver and local access requirements of this vulnerability.