CVE-2025-39730
Description
A flaw out of boundary read in the Linux kernel NFS functionality was found in the way connected user sends malicious data to the server. A remote user could use this flaw to crash the system.
Statement
A flaw was found in the NFS server implementation where nfs_fh_to_dentry() failed to properly validate the minimal filehandle length before accessing the embedded structure. An attacker with access to an exported NFS share could send a crafted filehandle, leading to out-of-bounds memory access and a potential kernel crash. This issue results in a remote denial of service against the NFS server. This flaw is limited to a missing bounds check in nfs_fh_to_dentry(), which causes an out-of-bounds read and a kernel crash.
Mitigation
To mitigate this issue, prevent module nfs from being loaded. Please see https://access.redhat.com/solutions/41278 for how to blacklist a kernel module to prevent it from loading automatically.
Common Vulnerability Scoring System (CVSS) Score Details
Info alert:Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 7.5 | 7.8 | N/A |
| Attack Vector | Network | Local | N/A |
| Attack Complexity | Low | Low | N/A |
| Privileges Required | None | Low | N/A |
| User Interaction | None | None | N/A |
| Scope | Unchanged | Unchanged | N/A |
| Confidentiality | None | High | N/A |
| Integrity Impact | None | High | N/A |
| Availability Impact | High | High | N/A |
Vector
Red Hat: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
NVD: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
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