CVE-2024-47737 is a vulnerability identified in the Linux kernel's NFS daemon (nfsd) component, specifically related to the handling of buffer space during Remote Procedure Call (RPC) operations. The flaw arises when the function xdr_reserve_space returns NULL due to insufficient buffer space, but the idmap_lookup function has already triggered a lookup_fn call that successfully invokes cache_get. In this scenario, the corresponding cache_put call, which should release or decrement the reference count for the cache entry obtained by cache_get, is missing. This omission can lead to resource mismanagement, such as memory leaks or stale cache entries, potentially degrading system performance or stability over time. The vulnerability does not directly indicate an immediate code execution or privilege escalation vector but represents a logic flaw in resource handling within the kernel's NFS server implementation. The issue was reviewed and fixed by kernel maintainers, including Jeff Layton, and is now published with no known exploits in the wild. The affected versions are identified by a specific commit hash repeated multiple times, indicating the vulnerability is present in certain kernel builds prior to the patch. No CVSS score has been assigned yet, and no patch links are provided in the data, but the vulnerability is recognized and documented by the Linux project and CISA enrichment confirms its validity.

For European organizations, the impact of CVE-2024-47737 primarily concerns systems running Linux kernels with NFS server functionality enabled, which is common in enterprise environments for file sharing and storage solutions. While the vulnerability itself does not appear to allow direct unauthorized access or code execution, the improper resource management could lead to degraded availability of NFS services due to resource exhaustion or memory leaks. This degradation could affect critical file sharing infrastructure, potentially disrupting business operations that rely on networked storage. Organizations with large-scale NFS deployments, especially in data centers or cloud environments, might experience performance issues or require more frequent system restarts to mitigate resource depletion. The absence of known exploits reduces immediate risk, but the vulnerability should be addressed promptly to prevent potential escalation or exploitation in combination with other vulnerabilities. Confidentiality and integrity impacts are minimal based on current information, but availability concerns warrant attention.

European organizations should prioritize updating their Linux kernels to the latest patched versions that address CVE-2024-47737 as soon as they become available. In the interim, administrators can monitor NFS server logs and system resource usage closely to detect unusual memory consumption or cache behavior indicative of this flaw. Limiting exposure by restricting NFS server access to trusted networks and clients can reduce risk. Additionally, implementing resource limits and watchdog mechanisms to restart or alert on abnormal NFS daemon behavior can help maintain service availability. Organizations should also review their kernel update policies to ensure timely deployment of security patches, especially for critical infrastructure components like NFS. Engaging with Linux distribution vendors for backported patches and advisories is recommended to ensure compatibility and stability during updates.