L2 network filtering bypass using stacked VLAN0 and LLC/SNAP headers with invalid lengths
CVE-2021-27861

4.7MEDIUM

Key Information:

Vendor

Ieee

Status
802.2
Draft-ietf-v6ops-ra-guard
P802.1q
Vendor
CVE Published:
27 September 2022

What is 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)

Affected Version(s)

802.2 802.2h-1997

draft-ietf-v6ops-ra-guard 08

P802.1Q D1.0

References

https://datatracker.ietf.org/doc/draft-ietf-v6ops-ra-guar...
https://standards.ieee.org/ieee/802.2/1048/
https://standards.ieee.org/ieee/802.1Q/10323/

CVSS V3.1

Score:
4.7
Severity:
MEDIUM
Confidentiality:
None
Integrity:
Low
Availability:
None
Attack Vector:
Adjacent Network
Attack Complexity:
Low
Privileges Required:
None
User Interaction:
None
Scope:
Changed

Timeline

  • Vulnerability published

  • Vulnerability Reserved

Credit

Etienne Champetier (@champtar) <[email protected]>
.