CVE-2021-28504

On Arista Strata family products which have “TCAM profile” feature enabled when Port IPv4 access-list has a rule which matches on “vxlan” as protocol then that rule and subsequent rules ( rules declared after it in ACL ) do not match on IP protocol fi ...

Description

On Arista Strata family products which have “TCAM profile” feature enabled when Port IPv4 access-list has a rule which matches on “vxlan” as protocol then that rule and subsequent rules ( rules declared after it in ACL ) do not match on IP protocol field as expected.

Remediation

Solution:

  • The recommended resolution is to upgrade to a remediated software version at your earliest convenience. Artista recommends customers move to the latest version of each release that contains all the fixes listed below. CVE-2021-28504 has been fixed in the following releases: 4.26.4F and later releases in the 4.26.x train 4.27.1M and later releases in the 4.27.x train

Workaround:

  • Replace "vxlan" IP protocol match with match on IP protocol "udp" and Layer 4 destination port for VxLAN encapsulated packets i.e 4789. If VXLAN L4 destination port number is not the default 4789 then use the configured L4 destination port number.

Categories

7.5
CVSS
Severity: High
CVSS 3.1 •
CVSS 2.0 •
EPSS 0.18%
Vendor Advisory arista.com
Affected: Arista Networks EOS
Published at:
Updated at:

References

Link Tags
https://www.arista.com/en/support/advisories-notices/security-advisories/15267-security-advisory-0073 mitigation vendor advisory

Frequently Asked Questions

What is the severity of CVE-2021-28504?
CVE-2021-28504 has been scored as a high severity vulnerability.
How to fix CVE-2021-28504?
To fix CVE-2021-28504: The recommended resolution is to upgrade to a remediated software version at your earliest convenience. Artista recommends customers move to the latest version of each release that contains all the fixes listed below. CVE-2021-28504 has been fixed in the following releases: 4.26.4F and later releases in the 4.26.x train 4.27.1M and later releases in the 4.27.x train
Is CVE-2021-28504 being actively exploited in the wild?
As for now, there are no information to confirm that CVE-2021-28504 is being actively exploited. According to its EPSS score, there is a ~0% probability that this vulnerability will be exploited by malicious actors in the next 30 days.
What software or system is affected by CVE-2021-28504?
CVE-2021-28504 affects Arista Networks EOS.
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