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. Functionality of normal MSDUs and A-MSDUs was also tested, and confirmed working, when using both an empty and 12-byte Mesh Address Extension field. It was also tested with mac80211_hwsim that A-MSDU attacks in non-mesh networks keep being detected and prevented. Note that the vulnerability being patched, and the defense being implemented, was also discussed in the following paper and in the following IEEE 802.11 presentation: https://papers.mathyvanhoef.com/wisec2025.pdf https://mentor.ieee.org/802.11/dcn/25/11-25-0949-00-000m-a-msdu-mesh-spoof-protection.docx
History

Mon, 18 Aug 2025 21:00:00 +0000

Type Values Removed Values Added
First Time appeared Linux
Linux linux Kernel
Vendors & Products Linux
Linux linux Kernel

Sat, 16 Aug 2025 11:15:00 +0000

Type Values Removed Values Added
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. Functionality of normal MSDUs and A-MSDUs was also tested, and confirmed working, when using both an empty and 12-byte Mesh Address Extension field. It was also tested with mac80211_hwsim that A-MSDU attacks in non-mesh networks keep being detected and prevented. Note that the vulnerability being patched, and the defense being implemented, was also discussed in the following paper and in the following IEEE 802.11 presentation: https://papers.mathyvanhoef.com/wisec2025.pdf https://mentor.ieee.org/802.11/dcn/25/11-25-0949-00-000m-a-msdu-mesh-spoof-protection.docx
Title wifi: prevent A-MSDU attacks in mesh networks
References

cve-icon MITRE

Status: PUBLISHED

Assigner: Linux

Published:

Updated: 2025-08-16T10:54:54.285Z

Reserved: 2025-04-16T04:51:24.022Z

Link: CVE-2025-38512

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Awaiting Analysis

Published: 2025-08-16T11:15:44.263

Modified: 2025-08-18T20:16:28.750

Link: CVE-2025-38512

cve-icon Redhat

No data.