CVE-2021-47083 is a vulnerability identified in the Linux kernel specifically within the pinctrl subsystem for MediaTek platforms. The issue arises from a global out-of-bounds access in the handling of virtual external interrupt (eint) numbers. When the virtual eint number exceeds the number of available GPIOs, the kernel attempts to access an array element 'desc[eint_n]' beyond its allocated bounds. This out-of-bounds access can lead to undefined behavior, including potential memory corruption. Such memory corruption could be exploited by a local attacker to cause a denial of service (kernel panic or system crash) or potentially escalate privileges by manipulating kernel memory structures. The vulnerability is rooted in improper bounds checking in the pinctrl driver code for MediaTek SoCs, which are commonly used in embedded devices and some Linux-based systems. The issue was resolved by correcting the bounds checking logic to ensure that the virtual eint number does not exceed the GPIO count, preventing the out-of-bounds access. No known exploits are currently reported in the wild, and no CVSS score has been assigned yet. The vulnerability affects specific Linux kernel versions containing the faulty commit identified by the given hashes. This vulnerability requires local access to the system and likely some level of privilege to trigger the fault, as it involves kernel-level driver code execution paths related to hardware interrupt handling.

For European organizations, the impact of CVE-2021-47083 depends largely on their use of Linux systems running on MediaTek hardware or embedded devices that incorporate the affected Linux kernel versions. Organizations using such devices in critical infrastructure, industrial control systems, or IoT deployments could face risks of system instability or denial of service if exploited. While the vulnerability does not appear to allow remote exploitation or direct data exfiltration, the potential for privilege escalation or kernel crashes could disrupt operations or provide a foothold for further attacks. Given the widespread use of Linux in servers, desktops, and embedded systems, the threat is more pronounced in environments where MediaTek-based Linux devices are deployed. European companies in telecommunications, manufacturing, and smart device sectors might be particularly exposed. The lack of known exploits reduces immediate risk, but the vulnerability should be addressed promptly to prevent future exploitation. The confidentiality impact is limited, but integrity and availability could be significantly affected if the vulnerability is exploited to corrupt kernel memory or cause system crashes.

To mitigate CVE-2021-47083, European organizations should: 1) Identify all Linux systems running on MediaTek hardware or using affected kernel versions by auditing device inventories and kernel versions. 2) Apply the official Linux kernel patches that fix the bounds checking in the pinctrl Mediatek driver as soon as they are available and tested. 3) For embedded or IoT devices where kernel updates are not straightforward, coordinate with device vendors to obtain firmware updates or mitigations. 4) Restrict local access to vulnerable systems to trusted users only, minimizing the risk of local exploitation. 5) Monitor system logs and kernel messages for signs of out-of-bounds access or kernel panics related to the pinctrl driver. 6) Employ kernel hardening techniques such as Kernel Address Space Layout Randomization (KASLR) and Kernel Page Table Isolation (KPTI) to reduce exploitation likelihood. 7) Incorporate this vulnerability into vulnerability management and patching workflows to ensure timely remediation. 8) Consider network segmentation and access controls to isolate critical devices running vulnerable kernels.