CVE-2025-47711 is a medium-severity vulnerability identified in the nbdkit server component used within Red Hat Enterprise Linux 10. The flaw is an off-by-one error occurring during the handling of plugin responses related to the status of data blocks. Specifically, when a client issues a request for a very large data range, and a plugin responds with an even larger single block, the nbdkit server fails to properly manage this condition. This results in a critical internal error that causes the server to crash or become unresponsive, leading to a denial-of-service (DoS) condition. The vulnerability does not impact confidentiality or integrity but affects availability by causing service disruption. Exploitation requires network access (AV:N), low attack complexity (AC:L), and privileges (PR:L), but no user interaction (UI:N). The vulnerability is present in versions 1.11.10, 1.40.0, and 1.42.0 of nbdkit shipped with Red Hat Enterprise Linux 10. No known exploits are currently in the wild, and no patches or mitigations have been explicitly linked yet. The CVSS score of 4.3 reflects the medium severity, primarily due to the denial-of-service impact and the requirement for some privileges to exploit.

For European organizations, the primary impact of CVE-2025-47711 is service availability disruption in environments utilizing Red Hat Enterprise Linux 10 with affected nbdkit versions. Organizations relying on nbdkit for network block device services, such as virtualization platforms, cloud infrastructure, or storage solutions, may experience outages or degraded performance if exploited. This can affect critical business operations, especially in sectors like finance, healthcare, and government where uptime is essential. Although the vulnerability does not allow data leakage or modification, repeated or targeted exploitation could lead to significant operational disruptions and potential cascading effects on dependent services. The requirement for some level of privilege reduces the risk of widespread exploitation but insider threats or compromised accounts could leverage this flaw. Given the widespread use of Red Hat Enterprise Linux in European enterprise and public sector environments, the impact could be notable if not addressed promptly.

To mitigate CVE-2025-47711, European organizations should: 1) Identify and inventory all systems running Red Hat Enterprise Linux 10 with affected nbdkit versions (1.11.10, 1.40.0, 1.42.0). 2) Monitor vendor advisories closely for patches or updates addressing this vulnerability and apply them promptly once available. 3) Restrict network access to nbdkit services to trusted and authenticated users only, minimizing exposure to untrusted networks. 4) Implement strict privilege management to limit the number of users with the required privileges to exploit this flaw. 5) Employ network-level protections such as firewalls and intrusion detection systems to detect anomalous large data range requests that could trigger the vulnerability. 6) Consider temporary workarounds such as disabling or isolating nbdkit services if they are not critical or can be replaced until a patch is applied. 7) Conduct regular security audits and monitoring to detect potential exploitation attempts or service disruptions related to this vulnerability.