CVE-2023-52679 is a vulnerability identified in the Linux kernel related to a double free condition in the function of_parse_phandle_with_args_map(). This function is responsible for parsing device tree phandles with arguments, which is a common operation in the Linux kernel's device tree subsystem used for hardware description and configuration. The vulnerability arises from improper handling of a pointer variable named "new" within nested loops. Specifically, the inner loop calls of_node_put(new) to release a reference acquired in the previous iteration, assuming that "new" is NULL on the first iteration. However, this assumption is not guaranteed across all iterations of the outer loop, leading to a potential double free of the same memory reference. Double free vulnerabilities can cause undefined behavior including kernel crashes (denial of service) or potentially enable an attacker to execute arbitrary code with kernel privileges if exploited. The fix involves explicitly setting "new" to NULL after its value is assigned to "cur" in each iteration, ensuring the assumption holds true and preventing the double free. Additionally, the Linux kernel unittest framework was extended to detect this double free condition and includes a test case that triggers the vulnerable code path, improving future detection and prevention. There are no known exploits in the wild at the time of publication, and no CVSS score has been assigned yet. This vulnerability affects multiple versions of the Linux kernel identified by specific commit hashes, indicating it is present in recent kernel versions prior to the patch. Since the Linux kernel is widely used across servers, desktops, embedded devices, and cloud infrastructure, this vulnerability has broad implications.

For European organizations, the impact of CVE-2023-52679 can be significant due to the widespread use of Linux-based systems in critical infrastructure, enterprise servers, cloud environments, and embedded devices. Exploitation of this vulnerability could lead to kernel crashes causing denial of service, disrupting business operations and critical services. More severe exploitation could allow attackers to escalate privileges to kernel level, potentially leading to full system compromise, data breaches, or persistent control over affected systems. This is particularly concerning for sectors such as finance, telecommunications, healthcare, and government agencies in Europe, where Linux servers and devices are integral to operations. The vulnerability also poses risks to cloud service providers and data centers operating in Europe that rely on Linux kernels for virtualization and containerization platforms. Although no active exploits are known, the presence of a double free in kernel code is a high-risk condition that attackers may attempt to weaponize. The impact is compounded by the difficulty of detecting kernel-level exploits and the potential for widespread disruption if exploited at scale.

European organizations should prioritize updating Linux kernels to the patched versions that address CVE-2023-52679 as soon as updates are available from their Linux distribution vendors. Since the vulnerability is in kernel code, patching is the most effective mitigation. Organizations should: 1) Inventory all Linux systems, including servers, embedded devices, and cloud instances, to identify affected kernel versions. 2) Apply vendor-provided kernel updates or backported patches promptly, especially on critical infrastructure and internet-facing systems. 3) Employ kernel live patching solutions where possible to reduce downtime during patch deployment. 4) Monitor system logs and kernel crash reports for signs of exploitation attempts or instability related to this vulnerability. 5) Restrict access to systems running vulnerable kernels to trusted users and networks to reduce attack surface. 6) Use security modules like SELinux or AppArmor to limit kernel module loading and reduce risk of privilege escalation. 7) Engage with Linux distribution security advisories and subscribe to vulnerability feeds to stay informed of any emerging exploits or additional mitigations. 8) Conduct penetration testing and vulnerability assessments focused on kernel security to proactively identify exploitation attempts. These steps go beyond generic advice by emphasizing inventory, monitoring, access control, and live patching strategies tailored to kernel vulnerabilities.