CVE-2021-47614 is a vulnerability identified in the Linux kernel's RDMA (Remote Direct Memory Access) subsystem, specifically within the iWARP RDMA driver component (irdma). The issue arises in the function add_pble_prm, where a user-after-free condition occurs. This happens when the function irdma_hmc_sd_one fails, leading to the premature freeing of a memory chunk while it is still referenced in the PBLE (Page Buffer List Entry) info list. The flaw is due to improper handling of the chunk's lifecycle: the chunk is added to the PBLE info list before the successful setting of the SD (Segment Descriptor) in irdma_hmc_sd_one. If the setting fails, the chunk is freed but remains on the list, resulting in a use-after-free scenario. This type of vulnerability can lead to undefined behavior, including potential kernel crashes, memory corruption, or escalation of privileges if exploited. The patch involves modifying the code to add the chunk entry to the PBLE info list only after the SD has been successfully set, preventing the use-after-free condition. Although no known exploits are reported in the wild, the vulnerability affects Linux kernel versions identified by the commit hash e8c4dbc2fcacf5a7468d312168bb120c27c38b32 and potentially others in the same timeframe. The vulnerability is significant because the Linux kernel is widely used in servers, cloud infrastructure, and enterprise environments, and RDMA is critical for high-performance computing and data center operations.

For European organizations, the impact of CVE-2021-47614 could be substantial, especially for those relying on Linux-based servers and infrastructure that utilize RDMA technology for high-throughput, low-latency networking, such as in financial services, telecommunications, research institutions, and cloud service providers. Exploitation of this vulnerability could allow attackers to cause kernel crashes leading to denial of service or potentially execute arbitrary code with kernel privileges, compromising system confidentiality, integrity, and availability. This could result in data breaches, disruption of critical services, and loss of trust. Given the widespread use of Linux in European data centers and cloud environments, the vulnerability poses a risk to critical infrastructure and enterprise operations. However, the absence of known exploits reduces immediate risk, but the potential for future exploitation remains, especially if attackers develop targeted exploits.

European organizations should prioritize applying the official Linux kernel patches that address CVE-2021-47614 as soon as they become available. Beyond patching, organizations should audit their use of RDMA-enabled hardware and software to ensure that only necessary services are exposed and that access controls are strictly enforced. Employ kernel hardening techniques such as Kernel Address Space Layout Randomization (KASLR), and enable security modules like SELinux or AppArmor to limit the impact of potential kernel exploits. Monitoring kernel logs and system behavior for anomalies related to RDMA operations can help detect exploitation attempts early. Additionally, organizations should maintain strict network segmentation for systems using RDMA to reduce attack surface and exposure. Regular vulnerability scanning and penetration testing focusing on kernel-level vulnerabilities can further enhance defense.