CVE-2023-52922 is a high-severity use-after-free (UAF) vulnerability identified in the Linux kernel's CAN (Controller Area Network) subsystem, specifically within the Broadcom (bcm) driver implementation. The vulnerability arises in the bcm_proc_show() function, which is responsible for displaying procfs entries related to the bcm driver. The root cause is that the bcm_op structure is freed prematurely before the procfs entry is removed in the bcm_release() function. This leads to bcm_proc_show() potentially accessing memory that has already been freed, causing a use-after-free condition. The vulnerability was detected through Kernel Address Sanitizer (KASAN) reports indicating slab-use-after-free errors during read operations initiated by user-space processes (e.g., the 'cat' command reading procfs entries). The call trace shows that the issue occurs during a sequence of kernel functions handling procfs reads and socket message sends. Exploiting this vulnerability could allow an attacker with local privileges (low privilege required) to execute arbitrary code in kernel space or cause a denial of service by crashing the kernel, impacting confidentiality, integrity, and availability. The CVSS v3.1 score is 7.8 (high), reflecting the vulnerability's significant impact and relatively low complexity to exploit, requiring local access but no user interaction. The vulnerability affects Linux kernel versions identified by the commit hash ffd980f976e7fd666c2e61bf8ab35107efd11828 and similar builds. No known exploits are currently reported in the wild, but the nature of the flaw and its presence in a widely used kernel subsystem make it a critical concern for systems running affected Linux kernels, especially those using the bcm CAN driver.

For European organizations, this vulnerability poses a substantial risk, particularly for industries and sectors relying on Linux-based embedded systems, automotive control units, industrial automation, and IoT devices that utilize the CAN protocol and Broadcom hardware components. Exploitation could lead to privilege escalation, kernel-level code execution, or system crashes, potentially disrupting critical infrastructure, manufacturing processes, or automotive systems. Given the widespread use of Linux in enterprise servers, cloud environments, and embedded devices across Europe, the vulnerability could impact data confidentiality, system integrity, and availability. Organizations in sectors such as automotive manufacturing, industrial control systems, telecommunications, and critical infrastructure are at heightened risk. The requirement for local privileges limits remote exploitation but does not eliminate risk, as insider threats or compromised local accounts could leverage this flaw. Additionally, the vulnerability could be used as a stepping stone for further attacks within a networked environment, amplifying its impact on European enterprises and public sector entities.

To mitigate CVE-2023-52922, European organizations should prioritize the following actions: 1) Apply the official Linux kernel patches that address the bcm_proc_show() use-after-free vulnerability as soon as they become available from trusted Linux distribution vendors or the upstream kernel. 2) For embedded and IoT devices using affected Linux kernels, coordinate with hardware and software vendors to obtain updated firmware or kernel versions incorporating the fix. 3) Restrict local access to systems running vulnerable kernels by enforcing strict access controls, limiting user privileges, and monitoring for suspicious local activity. 4) Implement kernel hardening techniques such as Kernel Address Sanitizer (KASAN) in development and testing environments to detect similar memory safety issues proactively. 5) Conduct thorough audits of systems using the CAN protocol and Broadcom drivers to identify vulnerable devices and prioritize remediation. 6) Employ runtime security tools capable of detecting anomalous kernel behavior or crashes indicative of exploitation attempts. 7) Educate system administrators and security teams about the vulnerability specifics to enhance incident detection and response capabilities. These targeted measures go beyond generic patching by focusing on access control, vendor coordination, and proactive detection tailored to the vulnerability's characteristics.