CVE-2021-47029 is a vulnerability identified in the Linux kernel, specifically within the mt76 wireless driver subsystem that supports MediaTek Wi-Fi chipsets. The issue arises in the mt76_connac_mcu_uni_add_dev function, which is responsible for adding a monitor interface to the wireless device. The vulnerability manifests as a kernel warning and potential instability when attempting to add a monitor interface, as evidenced by the kernel warning trace logs included in the description. The problem is related to improper handling within the mt76_connac_mcu_uni_add_dev routine, which could lead to kernel warnings or crashes during the initialization of the wireless device, particularly during the EEPROM initialization phase of the mt7921e driver. Although the vulnerability does not appear to be a direct code execution or privilege escalation flaw, the kernel warnings and potential crashes can cause denial of service (DoS) conditions by destabilizing the wireless networking stack. The vulnerability affects Linux kernel versions containing the affected commit (d0e274af2f2e44b9d496f5d2c0431fdd2ea76fb8). No public exploits are currently known, and no CVSS score has been assigned. The issue was resolved by fixing the kernel warning in the mt76_connac_mcu_uni_add_dev function, improving the robustness of the wireless driver when adding monitor interfaces. This vulnerability is relevant for systems using MediaTek mt76 wireless chipsets, especially those running Linux kernels prior to the patch. The impact is primarily on system stability and availability of wireless interfaces rather than confidentiality or integrity. The vulnerability is triggered locally when adding a monitor interface, which typically requires administrative privileges and user interaction.

For European organizations, the impact of CVE-2021-47029 is primarily related to the availability and stability of Linux-based systems using MediaTek mt76 wireless chipsets. Organizations relying on Linux servers, embedded devices, or network equipment with affected wireless drivers may experience unexpected kernel warnings or crashes when configuring monitor interfaces, potentially leading to denial of service conditions. This could disrupt wireless connectivity or network monitoring capabilities, impacting operational continuity. While the vulnerability does not directly expose sensitive data or allow privilege escalation, the resulting instability could affect critical infrastructure components, especially in sectors like telecommunications, manufacturing, and IoT deployments where Linux and MediaTek chipsets are common. The requirement for local administrative access to trigger the issue limits the attack surface, but insider threats or compromised accounts could exploit this vulnerability to degrade system performance. Additionally, the lack of known exploits reduces immediate risk; however, unpatched systems remain vulnerable to accidental or intentional triggering of the flaw. The impact on confidentiality and integrity is minimal, but availability concerns warrant timely patching in environments where wireless interface stability is critical.

To mitigate CVE-2021-47029, European organizations should: 1) Identify and inventory Linux systems using MediaTek mt76 wireless chipsets, particularly those running kernel versions prior to the fix commit (d0e274af2f2e44b9d496f5d2c0431fdd2ea76fb8). 2) Apply the latest Linux kernel updates or patches that address this vulnerability to ensure the mt76_connac_mcu_uni_add_dev function is corrected. 3) Restrict administrative privileges to trusted personnel only, minimizing the risk of unauthorized local triggering of the vulnerability. 4) Monitor system logs for kernel warnings related to mt76 wireless drivers and investigate any anomalies promptly. 5) For critical systems where wireless monitoring interfaces are essential, consider implementing redundancy or failover mechanisms to maintain network availability during potential disruptions. 6) Engage with hardware vendors and Linux distribution maintainers to confirm the presence of patches and coordinate timely deployment. 7) In environments where immediate patching is not feasible, avoid adding monitor interfaces on affected devices to prevent triggering the vulnerability. These targeted steps go beyond generic advice by focusing on the specific driver and kernel versions involved, administrative controls, and operational practices to reduce exposure and impact.