CVE-2021-27854 : Exploit Details and Defense Strategies
CVE-2021-27854 relates to a vulnerability allowing the bypass of Layer 2 network filters using specific headers and frame translations. Learn about affected systems, exploitation, and mitigation.
A vulnerability affecting Layer 2 network filtering capabilities, specifically bypassing IPv6 RA guard using certain headers and frame translations.
Understanding CVE-2021-27854
This CVE relates to a method of bypassing Layer 2 network filtering mechanisms through intricate header manipulations.
What is CVE-2021-27854?
The CVE-2021-27854 vulnerability allows attackers to circumvent IPv6 RA guard and similar protections by utilizing VLAN 0 headers, LLC/SNAP headers, and manipulating Ethernet to Wifi frame conversions.
The Impact of CVE-2021-27854
The vulnerability affects specific versions of IETF and IEEE products, potentially leading to unauthorized network access and data interception.
Technical Details of CVE-2021-27854
This section delves into the specific technical aspects of CVE-2021-27854.
Vulnerability Description
CVE-2021-27854 enables threat actors to evade Layer 2 network filtering controls by leveraging stacked VLAN 0 headers, LLC/SNAP headers, and conversions between Ethernet and Wifi frames.
Affected Systems and Versions
The vulnerability impacts versions such as P802.1Q D1.0, draft-ietf-v6ops-ra-guard 08, and IEEE 802.2 802.2h-1997, under the vendors IETF and IEEE.
Exploitation Mechanism
By strategically combining VLAN 0 headers, LLC/SNAP headers, and manipulating Ethernet to Wifi frame translations, attackers can subvert network security measures.
Mitigation and Prevention
Discover how to mitigate and prevent the exploitation of CVE-2021-27854 in the following section.
Immediate Steps to Take
Organizations should implement network monitoring, restrict VLAN 0 usage, and apply available vendor patches to mitigate the vulnerability's exploitation.
Long-Term Security Practices
Ensure ongoing security awareness training, conduct regular vulnerability assessments, and maintain up-to-date network equipment to bolster long-term security.
Patching and Updates
Stay informed about security advisories released by IETF and IEEE, promptly apply patches, and monitor industry sources for further guidance on securing against CVE-2021-27854.