What’s Vulnerable › Vulnerabilities

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 ...

• Severity: high (CVSS 7.5 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.7% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2022-04-01 · updated 2026-06-17
• Weakness: CWE-284

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.

Affected products

• Arista Networks EOS: from 4.26 before 4.26.4m; from 4.27 before 4.27.1f — fixed in 4.26.4m, 4.27.1f

How to fix

Upgrade to a fixed version: Arista Networks EOS 4.26.4m, 4.27.1f. Check the vendor advisory for mitigations.

References

• https://www.arista.com/en/support/advisories-notices/security-advisories/15267-security-advisory-0073
• https://www.arista.com/en/support/advisories-notices/security-advisories/15267-security-advisory-0073

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