Vulnerability Monitor

The vendors, products, and vulnerabilities you care about

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, and converting frames from Ethernet to Wifi and its reverse.

Published

2022-09-27T19:15:09.240

Last Modified

2025-05-21T15:15:54.267

Status

Modified

Source

[email protected]

Severity

CVSSv3.1: 4.7 (MEDIUM)

Weaknesses

Type: Secondary
CWE-290
Type: Primary
CWE-290

Affected Vendors & Products

Type	Vendor	Product	Version/Range	Vulnerable?
Application	ieee	ieee_802.2	≤ 802.2h-1997	Yes
Application	ietf	p802.1q	≤ d1.0	Yes

References

https://blog.champtar.fr/VLAN0_LLC_SNAP/ ([email protected])
https://datatracker.ietf.org/doc/draft-ietf-v6ops-ra-guard/08/ Vendor Advisory ([email protected])
https://kb.cert.org/vuls/id/855201 ([email protected])
https://standards.ieee.org/ieee/802.1Q/10323/ Vendor Advisory ([email protected])
https://standards.ieee.org/ieee/802.2/1048/ Vendor Advisory ([email protected])
https://blog.champtar.fr/VLAN0_LLC_SNAP/ (af854a3a-2127-422b-91ae-364da2661108)
https://datatracker.ietf.org/doc/draft-ietf-v6ops-ra-guard/08/ Vendor Advisory (af854a3a-2127-422b-91ae-364da2661108)
https://kb.cert.org/vuls/id/855201 (af854a3a-2127-422b-91ae-364da2661108)
https://standards.ieee.org/ieee/802.1Q/10323/ Vendor Advisory (af854a3a-2127-422b-91ae-364da2661108)
https://standards.ieee.org/ieee/802.2/1048/ Vendor Advisory (af854a3a-2127-422b-91ae-364da2661108)