CVE-2021-47381 is a vulnerability identified in the Linux kernel, specifically within the ASoC (ALSA System on Chip) Sound Open Firmware (SOF) component. The issue pertains to the handling of DSP (Digital Signal Processor) oops stack dump output. The vulnerability arises from improper management of the buffer argument passed to the hex_dump_to_buffer() function, which is used to format and output diagnostic information during error conditions. Additionally, the vulnerability involves the use of stack addresses in the dump error output, which can inadvertently expose sensitive kernel stack information. This flaw could potentially lead to information leakage or aid attackers in crafting more effective exploits by revealing kernel memory layout details. The vulnerability has been addressed by correcting the buffer argument handling and eliminating the exposure of stack addresses in the error output. No known exploits are currently reported in the wild, and the vulnerability was reserved and published in May 2024. The affected versions correspond to specific Linux kernel commits identified by their hashes. The lack of a CVSS score indicates that the vulnerability might be considered low risk or not fully assessed yet, but the nature of the flaw suggests a moderate concern primarily related to information disclosure rather than direct code execution or privilege escalation.

For European organizations, the impact of CVE-2021-47381 is primarily related to potential information disclosure within systems running vulnerable Linux kernel versions that include the affected ASoC SOF component. Organizations relying on Linux-based infrastructure, especially those using embedded systems, audio processing devices, or specialized hardware leveraging the SOF framework, could be at risk of leaking kernel stack information. While this does not directly lead to system compromise, the exposure of kernel memory layout can facilitate further targeted attacks, such as privilege escalation or kernel exploitation, by providing attackers with valuable reconnaissance data. This is particularly relevant for sectors with high security requirements such as telecommunications, industrial control systems, and critical infrastructure operators in Europe. However, since no active exploits are known, the immediate risk remains low, but the vulnerability should be addressed promptly to prevent future exploitation. The impact on confidentiality is moderate, while integrity and availability impacts are minimal.

European organizations should ensure that their Linux kernel versions are updated to include the patch that fixes CVE-2021-47381. Specifically, they should track and apply updates from their Linux distribution vendors that address the ASoC SOF component's handling of DSP oops stack dumps. For embedded or specialized devices that may not receive regular updates, organizations should coordinate with hardware vendors or consider kernel recompilation with the fix applied. Additionally, organizations should audit their systems to identify the presence of the affected kernel versions and the use of SOF components. Monitoring system logs for unusual DSP oops or error dump activity can help detect attempts to exploit this vulnerability. Employing kernel hardening techniques and restricting access to diagnostic interfaces can further reduce the risk of information leakage. Finally, organizations should maintain a robust patch management process to promptly incorporate kernel security updates.