CVE-2021-27854: L2 network filtering bypass using stacked VLAN0, LLC/SNAP headers, and Ethernet to Wifi frame translation
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.
Affected Software
Event History
Frequently Asked Questions
What is CVE-2021-27854?
CVE-2021-27854 is a vulnerability that allows bypassing layer 2 network filtering capabilities such as IPv6 RA guard using combinations of VLAN 0 headers, LLC/SNAP headers, and converting frames from Ethernet to Wifi and its reverse.
What is the severity of CVE-2021-27854?
The severity of CVE-2021-27854 is medium with a severity value of 4.7.
How can CVE-2021-27854 be exploited?
CVE-2021-27854 can be exploited by using combinations of VLAN 0 headers, LLC/SNAP headers, and converting frames from Ethernet to Wifi and its reverse to bypass layer 2 network filtering capabilities such as IPv6 RA guard.
What software is affected by CVE-2021-27854?
CVE-2021-27854 affects IEEE 802.2 with version up to and including 802.2h-1997, and IETF P802.1q with version up to and including d1.0.
How can I fix CVE-2021-27854?
To fix CVE-2021-27854, it is recommended to apply the necessary patches or updates provided by the respective vendors or software developers.