CVE-2025-38512

Technical Description

In the Linux kernel, the following vulnerability has been resolved:

wifi: prevent A-MSDU attacks in mesh networks

This patch is a mitigation to prevent the A-MSDU spoofing vulnerability

for mesh networks. The initial update to the IEEE 802.11 standard, in

response to the FragAttacks, missed this case (CVE-2025-27558). It can

be considered a variant of CVE-2020-24588 but for mesh networks.

This patch tries to detect if a standard MSDU was turned into an A-MSDU

by an adversary. This is done by parsing a received A-MSDU as a standard

MSDU, calculating the length of the Mesh Control header, and seeing if

the 6 bytes after this header equal the start of an rfc1042 header. If

equal, this is a strong indication of an ongoing attack attempt.

This defense was tested with mac80211_hwsim against a mesh network that

uses an empty Mesh Address Extension field, i.e., when four addresses

are used, and when using a 12-byte Mesh Address Extension field, i.e.,

when six addresses are used. Functional

Remediation

Check the references section for vendor advisories and patches from linux. Update linux_kernel to the latest patched version. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

Affected Products

References