Riskcovery

CVE-2021-27854

L2 network filtering bypass using stacked VLAN0, LLC/SNAP headers, and Ethernet to Wifi frame translation

State
Published
Severity
4.7 Medium
Published
Sep 27, 2022
Updated
Nov 4, 2025
Reserved
Mar 1, 2021

Read the record on cve.org

Description

Layer 2 network filtering capabilities such as IPv6 RA guard can be bypassed using combinations of VLAN 0 headers, LLC/SNAP headers, and converting frames from Ethernet to Wifi and its reverse.

Scores

CVSSScoreVectorSource
3.14.7 MediumCVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:NCISA-ADP

Weaknesses

  • CWE-290 Authentication Bypass by Spoofing

Affected Products

ProductVersions
P802.1QIETF
  • D1.0 through D1.0Affected
draft-ietf-v6ops-ra-guardIETF
  • 08 through 08Affected
802.2IEEE
  • 802.2h-1997 through 802.2h-1997Affected

References

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