Technical Advisory – L2 network security controls can be bypassed using VLAN 0 stacking and/or 802.3 headers

Externe Referenz

CVE-2021-27853 Layer 2 network filtering capabilities such as IPv6 RA guard or ARP inspection can be bypassed using combinations of VLAN 0 headers and LLC/SNAP headers.
CVE-2021-27854 Layer 2 network filtering capabilities such as IPv6 RA guard can be bypassed using combinations of VLAN 0 headers, LLC/SNAP headers in Ethernet to Wifi frame translation and the reverse Wifi to Ethernet.
CVE-2021-27861 Layer 2 network filtering capabilities such as IPv6 RA guard can be bypassed using LLC/SNAP headers with invalid length (and optionally VLAN0 headers).
CVE-2021-27862 Layer 2 network filtering capabilities such as IPv6 RA guard can be bypassed using LLC/SNAP headers with invalid length and Ethernet to Wifi frame conversion (and optionally VLAN0 headers).

Folgender Status ist das Ergebnis einer internen Rücksprache mit Kollegen aus R&D. Ein offizielles Security Advisory ist derzeit nicht vorgesehen.