CVE-2022-49711 is a high-severity use-after-free vulnerability found in the Linux kernel, specifically within the Freescale Management Complex (fsl-mc) bus driver code. The issue arises in the function fsl_mc_bus_remove(), where a pointer to mc->root_mc_bus_dev->mc_io is passed to the function fsl_destroy_mc_io(). However, at this point in execution, mc->root_mc_bus_dev has already been freed by the preceding call to fsl_mc_device_remove(). This results in a use-after-free condition, which is detected by Kernel Address Sanitizer (KASAN). The root cause is that the code references a freed memory object, leading to undefined behavior including potential memory corruption. The fix involves storing the mc_io reference in a local variable before the root_mc_bus_dev is freed, ensuring that the pointer passed to fsl_destroy_mc_io() is valid. This vulnerability is tracked under CWE-416 (Use After Free) and affects Linux kernel versions prior to the patch, including versions older than 5.15 which require a reworked patch. The CVSS v3.1 base score is 7.8, indicating high severity, with attack vector Local (AV:L), low attack complexity (AC:L), requiring low privileges (PR:L), no user interaction (UI:N), unchanged scope (S:U), and high impact on confidentiality, integrity, and availability (C:H/I:H/A:H). No known exploits are currently reported in the wild. The vulnerability could be exploited by a local attacker with limited privileges to execute arbitrary code or cause denial of service by triggering kernel memory corruption. The affected component, fsl-mc-bus, is related to Freescale/NXP Management Complex devices, which are specialized hardware components used in embedded systems and networking equipment running Linux kernels with this driver enabled.

For European organizations, the impact of CVE-2022-49711 depends largely on the deployment of Linux systems running kernels with the vulnerable fsl-mc-bus driver enabled. This vulnerability can lead to privilege escalation, arbitrary code execution in kernel context, or system crashes, which could disrupt critical infrastructure, embedded systems, or network appliances. Organizations in sectors such as telecommunications, industrial control systems, automotive, and defense that utilize NXP/Freescale-based hardware running Linux are at higher risk. Exploitation could result in loss of confidentiality, integrity, and availability of systems, potentially leading to data breaches, operational downtime, or compromised control systems. Given the local attack vector, insider threats or attackers with initial access to affected systems pose the greatest risk. The absence of known exploits reduces immediate threat but does not eliminate risk, especially as attackers may develop exploits over time. The requirement for local access means remote exploitation is unlikely without prior compromise, but lateral movement within networks could leverage this vulnerability to escalate privileges.

European organizations should implement the following specific mitigations: 1) Identify and inventory Linux systems running kernels with the fsl-mc-bus driver enabled, particularly those using NXP/Freescale Management Complex hardware. 2) Apply the official Linux kernel patches that fix CVE-2022-49711 as soon as they become available, ensuring that the patch is correctly backported for kernels older than version 5.15 if applicable. 3) Restrict local access to critical systems by enforcing strict access controls, using multi-factor authentication, and monitoring for unauthorized local logins. 4) Employ kernel hardening techniques such as enabling Kernel Address Sanitizer (KASAN) in testing environments to detect similar issues proactively. 5) Monitor system logs and kernel messages for signs of memory corruption or unusual behavior that could indicate exploitation attempts. 6) For embedded or specialized devices where patching is delayed or not feasible, consider network segmentation and isolation to limit exposure. 7) Engage with hardware and software vendors to confirm patch availability and coordinate timely updates. 8) Incorporate this vulnerability into vulnerability management and incident response plans to ensure rapid detection and remediation.