CVEvulnerability
CVE-2021-27861
4.7 MEDIUM
Official page ↗
- Status
- Modified
- Published
- 2022-09-27
- Last modified
- 2026-06-17
- Assigner
- [email protected]
- CVSS 3.1 ([email protected])
- 4.7 MEDIUM — CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N
- CVSS 3.1 (134c704f-9b21-4f2e-91b3-4a467353bcc0)
- 4.7 MEDIUM — CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N
- Weaknesses
- CWE-130, CWE-290
Description
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 configurations
• ieee ieee 802.2 (<= 802.2h-1997)
• ietf p802.1q (<= d1.0)
Related
References
- https://blog.champtar.fr/VLAN0_LLC_SNAP/ blog.champtar.fr
- https://datatracker.ietf.org/doc/draft-ietf-v6ops-ra-guard/08/ Third Party Advisory
- https://kb.cert.org/vuls/id/855201 kb.cert.org
- https://standards.ieee.org/ieee/802.1Q/10323/ Third Party Advisory
- https://standards.ieee.org/ieee/802.2/1048/ Third Party Advisory
- https://blog.champtar.fr/VLAN0_LLC_SNAP/ blog.champtar.fr
- https://datatracker.ietf.org/doc/draft-ietf-v6ops-ra-guard/08/ Third Party Advisory
- https://kb.cert.org/vuls/id/855201 kb.cert.org
- https://standards.ieee.org/ieee/802.1Q/10323/ Third Party Advisory
- https://standards.ieee.org/ieee/802.2/1048/ Third Party Advisory
- https://www.kb.cert.org/vuls/id/855201 www.kb.cert.org