CVE-2021-27861

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Summary

CVECVE-2021-27861
StatePUBLIC
Assigner[email protected]
Source PriorityCVE Program / NVD first with legacy fallback
Published2022-09-27 19:15:00 UTC
Updated2022-10-12 13:15:00 UTC
DescriptionLayer 2 network filtering capabilities such as IPv6 RA guard can be bypassed using LLC/SNAP headers with invalid length (and optionally VLAN0 headers)

Risk And Classification

Problem Types: CWE-290

NVD Known Affected Configurations (CPE 2.3)

TypeVendorProductVersionUpdateEditionLanguage
Application Ieee Ieee 802.2 All All All All
Application Ietf P802.1q All All All All

References

ReferenceSourceLinkTags
IEEE SA - IEEE/ISO 802.2-1989 CONFIRM standards.ieee.org
VU#855201 - L2 network security controls can be bypassed using VLAN 0 stacking and/or 802.3 headers MISC kb.cert.org
draft-ietf-v6ops-ra-guard-08 - IPv6 Router Advertisement Guard CONFIRM datatracker.ietf.org
Layer 2 network security bypass using VLAN 0, LLC/SNAP headers and invalid length | blog.champtar.fr MISC blog.champtar.fr
IEEE SA - IEEE P802.1Q CONFIRM standards.ieee.org
CVE Program record CVE.ORG www.cve.org canonical
NVD vulnerability detail NVD nvd.nist.gov canonical, analysis

Vendor Comments And Credit

Discovery Credit

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

Legacy QID Mappings

  • 317246 Cisco Small Business Switches Bypass Configured First-hop Security (FHS) Vulnerability (cisco-sa-VU855201-J3z8CKTX)
  • 317252 Cisco Catalyst 6500 and 6800 Series Switches Bypass Configured First-hop Security (FHS) Vulnerability (cisco-sa-VU855201-J3z8CKTX)
  • 317253 Cisco Internetwork Operating System (IOS) XR Software Bypass Configured First-hop Security (FHS) Vulnerability (cisco-sa-VU855201-J3z8CKTX)
  • 43997 Arista EOS Multiple Vulnerabilities (SA0080)
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