2.1 KiB
CVE-2025-38512
Description
In the Linux kernel, the following vulnerability has been resolved:wifi: prevent A-MSDU attacks in mesh networksThis patch is a mitigation to prevent the A-MSDU spoofing vulnerabilityfor mesh networks. The initial update to the IEEE 802.11 standard, inresponse to the FragAttacks, missed this case (CVE-2025-27558). It canbe 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-MSDUby an adversary. This is done by parsing a received A-MSDU as a standardMSDU, calculating the length of the Mesh Control header, and seeing ifthe 6 bytes after this header equal the start of an rfc1042 header. Ifequal, this is a strong indication of an ongoing attack attempt.This defense was tested with mac80211_hwsim against a mesh network thatuses an empty Mesh Address Extension field, i.e., when four addressesare used, and when using a 12-byte Mesh Address Extension field, i.e.,when six addresses are used. Functionality of normal MSDUs and A-MSDUswas also tested, and confirmed working, when using both an empty and12-byte Mesh Address Extension field.It was also tested with mac80211_hwsim that A-MSDU attacks in non-meshnetworks keep being detected and prevented.Note that the vulnerability being patched, and the defense beingimplemented, was also discussed in the following paper and in thefollowing IEEE 802.11 presentation:https://papers.mathyvanhoef.com/wisec2025.pdfhttps://mentor.ieee.org/802.11/dcn/25/11-25-0949-00-000m-a-msdu-mesh-spoof-protection.docx
POC
Reference
No PoCs from references.