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OpenAdvisories
Medium · 4.7 CVE-2021-27853 EUVD-2021-14591GHSA-v8jg-p3fp-g968

L2 network filtering can be bypassed using stacked VLAN0 and LLC/SNAP headers

Published Sep 27, 2022 · Updated Nov 4, 2025 · Assigned by certcc

Description

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.

Affected products

VendorProductAffectedFixed
IEEE 802.2 802.2h-1997 – ≤ 802.2h-1997 —
IETF draft-ietf-v6ops-ra-guard 08 – ≤ 08 —
IETF P802.1Q D1.0 – ≤ D1.0 —

Advisories 1

References