How severe is CVE-2021-28505?

CVE-2021-28505 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-2021-28505 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (54th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-28505?

CVE-2021-28505 affects Arista Eos. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2021-28505?

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-2021-28505 published?

CVE-2021-28505 was published on 2022-04-14 and last updated on 2026-06-17.

CVE-2021-28505

CVE-2021-28505 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: 5.0
EPSS exploit prediction: 1% (54th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-863
Affected product: Arista Eos
Published: 2022-04-14
Last modified: 2026-06-17

Description

On affected Arista EOS platforms, if a VXLAN match rule exists in an IPv4 access-list that is applied to the ingress of an L2 or an L3 port/SVI, the VXLAN rule and subsequent ACL rules in that access list will ignore the specified IP protocol.

Frequently asked questions

What is CVE-2021-28505?: On affected Arista EOS platforms, if a VXLAN match rule exists in an IPv4 access-list that is applied to the ingress of an L2 or an L3 port/SVI, the VXLAN rule and subsequent ACL rules in that access list will ignore the specified IP protocol.
How severe is CVE-2021-28505?: CVE-2021-28505 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-2021-28505 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (54th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-28505?: CVE-2021-28505 affects Arista Eos. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-28505?: 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-2021-28505 published?: CVE-2021-28505 was published on 2022-04-14 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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