PT-2025-14302 · Linux+2 · Linux Kernel+2

Published 2025-03-01 · Updated 2026-01-20 · CVE-2025-21921

Positive Technologies (AI Summary)

CVSS v3.1

5.5

Medium

Base vector

AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Name of the Vulnerable Software and Affected Versions Linux kernel (affected versions not specified)

Description A vulnerability in the Linux kernel has been resolved, related to the ethtool netlink command. The issue occurs when the ethnl req get phydev() function is used to lookup a phy device, and the header parameter is NULL, causing a crash. This happens in the notify path after a ->set operation, where there are no request attributes available. The vulnerability is triggered when the tb array is NULL, such as in the ethnl notify path, and only affects the PLCA command.

Recommendations At the moment, there is no information about a newer version that contains a fix for this vulnerability.

Exploit

NULL Pointer Dereference

Weakness Enumeration

CWE-476

Related Identifiers

BDU:2025-04086

CVE-2025-21921

Affected Products

Astra Linux

Linux Kernel

Red Os

References · 24

• 🔥 https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/21xxx/CVE-2025-21921.json · Exploit
• https://bdu.fstec.ru/vul/2025-04086 · Security Note
• https://osv.dev/vulnerability/CVE-2025-21921 · Vendor Advisory
• http://repo.red-soft.ru/redos/8.0/x86_64/updates · Vendor Advisory
• https://osv.dev/vulnerability/UBUNTU-CVE-2025-21921 · Vendor Advisory
• https://linux.oracle.com/errata/ELSA-2025-20480.html · Vendor Advisory
• https://git.kernel.org/stable/c/1f458fa42c29144cef280e05bc49fc21b873d897 · Patch
• https://osv.dev/vulnerability/BELL-CVE-2025-21921 · Vendor Advisory
• https://git.kernel.org/stable/c/639c70352958735addbba5ae7dd65985da96e061 · Patch
• https://linux.oracle.com/errata/ELSA-2025-20530.html · Vendor Advisory
• https://nvd.nist.gov/vuln/detail/CVE-2025-21921 · Security Note
• https://git.kernel.org/stable/c/637399bf7e77797811adf340090b561a8f9d1213 · Patch
• https://osv.dev/vulnerability/DEBIAN-CVE-2025-21921 · Vendor Advisory
• https://cve.org/CVERecord?id=CVE-2025-21921 · Security Note
• https://security-tracker.debian.org/tracker/CVE-2025-21921 · Vendor Advisory