How severe is CVE-2021-28509?

CVE-2021-28509 has a CVSS 3.x base score of 6.1, rated medium severity. It is exploitable over network with low attack complexity, requires high privileges and user interaction. Impact on confidentiality is high, integrity high, and availability none.

Is CVE-2021-28509 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (35th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-28509?

CVE-2021-28509 primarily affects Arista Terminattr. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2021-28509?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

When was CVE-2021-28509 published?

CVE-2021-28509 was published on 2022-05-26 and last updated on 2026-06-17.

CVE-2021-28509

CVE-2021-28509 is a medium-severity vulnerability in Arista Terminattr with a CVSS 3.x base score of 6.1. 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-319.

Key facts

Severity: Medium (CVSS 3.x base score 6.1)
CVSS v2: 3.6
EPSS exploit prediction: 0% (35th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-319
Affected product: Arista Terminattr
Published: 2022-05-26
Last modified: 2026-06-17

Description

This advisory documents the impact of an internally found vulnerability in Arista EOS state streaming telemetry agent TerminAttr and OpenConfig transport protocols. The impact of this vulnerability is that, in certain conditions, TerminAttr might leak MACsec sensitive data in clear text in CVP to other authorized users, which could cause MACsec traffic to be decrypted or modified by other authorized users on the device.

Frequently asked questions

What is CVE-2021-28509?: This advisory documents the impact of an internally found vulnerability in Arista EOS state streaming telemetry agent TerminAttr and OpenConfig transport protocols. The impact of this vulnerability is that, in certain conditions, TerminAttr might leak MACsec sensitive data in clear text in CVP to other authorized users, which could cause MACsec traffic to be decrypted or modified by other authorized users on the device.
How severe is CVE-2021-28509?: CVE-2021-28509 has a CVSS 3.x base score of 6.1, rated medium severity. It is exploitable over network with low attack complexity, requires high privileges and user interaction. Impact on confidentiality is high, integrity high, and availability none.
Is CVE-2021-28509 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (35th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-28509?: CVE-2021-28509 primarily affects Arista Terminattr. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2021-28509?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2021-28509 published?: CVE-2021-28509 was published on 2022-05-26 and last updated on 2026-06-17.

References

https://www.arista.com/en/support/advisories-notices/security-advisories/15484-security-advisory-0077

Affected products (2)

cpe:2.3:a:arista:terminattr:*:*:*:*:*:*:*:*
cpe:2.3:o:arista:eos:*:*:*:*:*:*:*:*

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