CVE-2022-48966 is a vulnerability identified in the Linux kernel's networking subsystem, specifically within the Marvell Ethernet driver (mvneta). The issue arises in the function mvneta_config_rss(), which handles Receive Side Scaling (RSS) configuration. RSS is a technique used to distribute network processing load across multiple CPUs to improve performance. The vulnerability stems from improper bounds checking of the user-controlled value pp->indir[0], which is used as an index in the function mvneta_percpu_elect(). This value is used to check if a CPU is online via cpu_online(pp->rxq_def). However, without proper validation, an out-of-bounds read can occur if pp->indir[0] exceeds the size of the CPU bitmap. This can lead to reading memory beyond the intended bounds, potentially causing kernel crashes (denial of service) or exposing sensitive kernel memory contents. The vulnerability is rooted in insufficient input validation of user-supplied data passed to kernel space, a common source of security flaws in kernel drivers. Although no known exploits are currently reported in the wild, the flaw could be leveraged by a local attacker with the ability to interact with the network driver to cause system instability or information leakage. The vulnerability affects specific Linux kernel versions identified by commit hashes, indicating that it is present in certain recent kernel builds prior to the patch. The fix involves adding proper bounds checking to ensure that the index does not exceed the CPU bitmap size, preventing out-of-bounds memory access.

For European organizations, the impact of CVE-2022-48966 can be significant, especially for those relying on Linux-based infrastructure for critical network services. The vulnerability could be exploited to cause denial of service by crashing the kernel, leading to service outages and potential disruption of business operations. Additionally, the out-of-bounds read could expose sensitive kernel memory, potentially leaking information that could aid further attacks. Organizations running network appliances, servers, or embedded systems using affected Linux kernels with the mvneta driver are at risk. This includes telecom providers, data centers, cloud service providers, and enterprises with Linux-based networking equipment. The disruption or compromise of such systems could impact data confidentiality, integrity, and availability. Given the widespread use of Linux in Europe across various sectors, the vulnerability poses a moderate risk until patched. However, the requirement for local access or user interaction to trigger the flaw somewhat limits remote exploitation, reducing the immediate threat level to externally facing systems.

European organizations should prioritize updating their Linux kernels to versions that include the patch for CVE-2022-48966. Since the vulnerability is in the mvneta driver, organizations should identify systems using Marvell Ethernet hardware and verify kernel versions. Applying vendor-supplied kernel updates or recompiling kernels with the fix is essential. Network administrators should audit systems for unusual crashes or instability that could indicate exploitation attempts. Limiting local user access and enforcing strict privilege separation can reduce the risk of exploitation. Additionally, organizations should implement kernel hardening measures such as Kernel Address Space Layout Randomization (KASLR) and enable security modules like SELinux or AppArmor to mitigate potential impact. Monitoring kernel logs for suspicious activity related to network drivers can provide early detection. For embedded or specialized devices where patching is delayed, consider network segmentation or isolating vulnerable systems to minimize exposure.