How severe is CVE-2021-28504?

CVE-2021-28504 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity high, and availability none.

Is CVE-2021-28504 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (49th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-28504?

CVE-2021-28504 affects Arista Eos. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2021-28504?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

When was CVE-2021-28504 published?

CVE-2021-28504 was published on 2022-04-01 and last updated on 2026-06-17.

CVE-2021-28504

CVE-2021-28504 is a high-severity vulnerability in Arista Eos with a CVSS 3.x base score of 7.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-863.

Key facts

Severity: High (CVSS 3.x base score 7.5)
CVSS v2: 4.3
EPSS exploit prediction: 1% (49th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-863
Affected product: Arista Eos
Published: 2022-04-01
Last modified: 2026-06-17

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.

Frequently asked questions

What is 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 field as expected.
How severe is CVE-2021-28504?: CVE-2021-28504 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity high, and availability none.
Is CVE-2021-28504 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (49th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-28504?: CVE-2021-28504 affects Arista Eos. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-28504?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2021-28504 published?: CVE-2021-28504 was published on 2022-04-01 and last updated on 2026-06-17.

References

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

Affected products (1)

cpe:2.3:o:arista:eos:*:*:*:*:*:*:*:*

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