Vulnerability Details 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)
Exploit prediction scoring system (EPSS) score
EPSS Score 0.0
EPSS Ranking 0.3%
CVSS Severity
CVSS v3 Score 4.7
References
- https://blog.champtar.fr/VLAN0_LLC_SNAP/
- https://datatracker.ietf.org/doc/draft-ietf-v6ops-ra-guard/08/
- https://kb.cert.org/vuls/id/855201
- https://standards.ieee.org/ieee/802.1Q/10323/
- https://standards.ieee.org/ieee/802.2/1048/
- https://blog.champtar.fr/VLAN0_LLC_SNAP/
- https://datatracker.ietf.org/doc/draft-ietf-v6ops-ra-guard/08/
- https://kb.cert.org/vuls/id/855201
- https://standards.ieee.org/ieee/802.1Q/10323/
- https://standards.ieee.org/ieee/802.2/1048/
Products affected by CVE-2021-27861
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cpe:2.3:a:ieee:ieee_802.2:802.2h-1997
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cpe:2.3:a:ietf:p802.1q:d1.0