CVE-2024-23848 is a use-after-free vulnerability identified in the Linux kernel versions up to 6.7.1. The flaw exists within the CEC (Consumer Electronics Control) subsystem, specifically in the functions cec_queue_msg_fh located in the source files drivers/media/cec/core/cec-adap.c and drivers/media/cec/core/cec-api.c. Use-after-free vulnerabilities occur when a program continues to use memory after it has been freed, potentially leading to undefined behavior such as crashes or exploitation by attackers. In this case, the vulnerability affects the CEC driver, which is responsible for enabling communication between HDMI-connected devices to control each other. The CVSS 3.1 base score is 5.5 (medium severity), with the vector indicating that the attack requires local access (AV:L), low attack complexity (AC:L), low privileges (PR:L), no user interaction (UI:N), unchanged scope (S:U), no confidentiality or integrity impact (C:N/I:N), but high impact on availability (A:H). This means an attacker with limited privileges on the local system can exploit this flaw to cause denial of service by crashing the kernel or causing instability. There are no known exploits in the wild at the time of publication, and no patches have been linked yet. The vulnerability is categorized under CWE-416 (Use After Free). The lack of vendor or product information suggests this is a generic Linux kernel issue affecting multiple distributions using kernel versions up to 6.7.1. Given the kernel's central role, exploitation could lead to system crashes or reboots, impacting system availability.

For European organizations, this vulnerability poses a risk primarily to systems running vulnerable Linux kernel versions up to 6.7.1, especially those with media or HDMI-related functionalities enabled. While the impact is limited to availability (denial of service), this can disrupt critical services, especially in environments relying on Linux servers or embedded devices with HDMI/CEC capabilities, such as digital signage, media servers, or industrial control systems. The requirement for local access and low privileges means that attackers or malicious insiders with limited system access could exploit this to cause system instability or crashes, potentially leading to downtime. In sectors like finance, healthcare, or manufacturing, where uptime is critical, such disruptions could have operational and financial consequences. Additionally, the lack of confidentiality or integrity impact reduces the risk of data breaches but does not eliminate the risk of service interruptions. European organizations using Linux distributions that incorporate affected kernel versions should be vigilant, as the Linux kernel is widely deployed across enterprises and public sector infrastructure in Europe.

Organizations should monitor for official patches from Linux kernel maintainers and apply them promptly once available. In the interim, practical mitigations include: 1) Restricting local access to trusted users only, minimizing the risk of exploitation by unprivileged users. 2) Disabling or unloading the CEC kernel modules (cec, cec-core) if HDMI-CEC functionality is not required, thereby reducing the attack surface. 3) Employing kernel hardening techniques such as enabling kernel lockdown modes, SELinux/AppArmor policies to restrict access to device nodes related to CEC. 4) Monitoring system logs for unusual crashes or kernel oops messages related to CEC. 5) For embedded or specialized devices, consider firmware updates or vendor advisories that may address this issue. 6) Implementing robust local user account management and auditing to detect potential misuse. These steps go beyond generic advice by focusing on the specific subsystem affected and the attack vector requiring local access.