Medium severity · published Sep 27, 2022
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…
4.7
CVSS
0.7%
EPSS
No
On KEV
Description
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.
CVSS vector
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N
Attack vector
Adjacent
Complexity
Low
Privileges
None
User interaction
None
Confidentiality
None
Integrity
Low
Availability
None
Scope
Changed
Exploitation
Is it being used?
Exploit prediction (EPSS)0.7% · higher than 54% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
I8
Ieee 802.2 · Ieee
through 802.2h-1997 · source: NVD
P8
P802.1q · Ietf
through d1.0 · source: NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2021-27854
CVE.org
https://www.cve.org/CVERecord?id=CVE-2021-27854
blog.champtar.fr
https://blog.champtar.fr/VLAN0_LLC_SNAP/
Vendor Advisory
https://datatracker.ietf.org/doc/draft-ietf-v6ops-ra-guard/08/
kb.cert.org
https://kb.cert.org/vuls/id/855201
Vendor Advisory
https://standards.ieee.org/ieee/802.1Q/10323/
Vendor Advisory
https://standards.ieee.org/ieee/802.2/1048/
www.kb.cert.org
https://www.kb.cert.org/vuls/id/855201
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