CVE-2021-47347 is a high-severity vulnerability in the Linux kernel specifically affecting the wl1251 wireless driver component. The vulnerability arises from a buffer overflow condition in the function wl1251_cmd_scan, which calls memcpy without validating the length of the data being copied. This lack of boundary checking can lead to memory corruption, allowing an attacker with limited privileges (requires local privileges) to execute arbitrary code or cause a denial of service by crashing the kernel. The vulnerability is classified under CWE-120 (Classic Buffer Overflow) and impacts confidentiality, integrity, and availability of affected systems. The vulnerability is exploitable remotely over the network (AV:N) but requires low attack complexity (AC:L) and privileges (PR:L), with no user interaction needed (UI:N). The scope is unchanged (S:U), meaning the impact is confined to the vulnerable component within the same security scope. The CVSS v3.1 base score is 8.8, indicating a high severity. Although no known exploits are currently reported in the wild, the potential for exploitation exists due to the nature of the flaw and the widespread use of the Linux kernel in servers, desktops, and embedded devices. The fix involves adding proper length checks before memcpy operations to prevent buffer overflow. The affected versions correspond to specific Linux kernel commits prior to the patch. This vulnerability is particularly relevant for systems using the wl1251 wireless driver, which is commonly found in certain embedded and IoT devices running Linux.

For European organizations, this vulnerability poses a significant risk especially to those relying on Linux-based infrastructure with wireless capabilities using the wl1251 driver. Potential impacts include unauthorized code execution leading to system compromise, data breaches, and service outages. Critical infrastructure, telecommunications, and enterprises with embedded Linux devices could face operational disruptions. The confidentiality of sensitive data may be compromised if attackers leverage this flaw to escalate privileges or implant persistent malware. Integrity of systems and data could be undermined, and availability could be affected through denial-of-service conditions caused by kernel crashes. Given the Linux kernel's extensive deployment across servers, desktops, and IoT devices in Europe, the vulnerability could affect a broad range of sectors including finance, healthcare, manufacturing, and government. The requirement for local privileges reduces the attack surface somewhat, but insider threats or attackers gaining initial access through other means could exploit this vulnerability to deepen their foothold.

European organizations should prioritize patching Linux kernel versions that include the wl1251 driver to the latest secure releases where this vulnerability is fixed. Specifically, they should: 1) Identify all systems running affected Linux kernel versions with the wl1251 wireless driver, including embedded and IoT devices. 2) Apply vendor-supplied kernel updates or backported patches that include the length check fix in wl1251_cmd_scan. 3) Where immediate patching is not feasible, consider disabling the wl1251 wireless driver if not required to reduce attack surface. 4) Implement strict access controls and monitoring to detect unusual local privilege escalation attempts. 5) Employ kernel hardening techniques such as Address Space Layout Randomization (ASLR) and Kernel Page-Table Isolation (KPTI) to mitigate exploitation impact. 6) Conduct thorough vulnerability scanning and penetration testing focused on local privilege escalation vectors. 7) Maintain robust endpoint detection and response (EDR) capabilities to identify exploitation attempts. 8) Educate system administrators and security teams about this vulnerability and the importance of timely patching. These steps go beyond generic advice by focusing on driver-specific mitigation, device inventory, and layered defense strategies.