CVE-2021-28509Network attack vector

MACsec key exposure via cleartext telemetry streaming

Published May 26, 2022 · Updated Sep 16, 2024

Cleartext data exposure in affected Arista EOS and TerminAttr releases allows remote authenticated users to obtain MACsec keys through telemetry. When TerminAttr or the Octa gNMI provider streams device state, it includes MACsec sensitive data without excluding or protecting the configured key material. Exploitation requires TerminAttr or Octa and MACsec to be enabled, access to CloudVision or gNMI, and user interaction; exposed keys permit decryption or modification of protected traffic.

CVSS severity6.1
Medium
EPSS probability0.46%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Cleartext data exposure in affected Arista EOS and TerminAttr releases allows remote authenticated users to obtain MACsec keys through telemetry. When TerminAttr or the Octa gNMI provider streams device state, it includes MACsec sensitive data without excluding or protecting the configured key material. Exploitation requires TerminAttr or Octa and MACsec to be enabled, access to CloudVision or gNMI, and user interaction; exposed keys permit decryption or modification of protected traffic.

The record

CVE
CVE-2021-28509
Published
May 26, 2022
Updated
Sep 16, 2024
Vendor
Arista Networks
Product
Arista TerminAttr
Classifications
CWE-319, CWE-255
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. May 26, 2022CVE publishedPublication date reported by the CVE source.
  2. Sep 16, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=v1.10 <=v1.10.10
  2. Affected versionversion=v1.16 <=v1.16.7
  3. Affected versionversion=v1.19 <=v1.19.1

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Arista Networks · Arista TerminAttrversion=v1.10 <=v1.10.10; version=v1.16 <=v1.16.7; version=v1.19 <=v1.19.1
Arista Networks · Arista EOSversion=4.23 <=4.23.11; version=4.24 <=4.24.9; version=4.25 <=4.25.7; version=4.26 <=4.26.5; version=4.27 <=4.27.3

Published CVSS scores

3.6NIST NVDAV:N/AC:H/Au:S/C:P/I:P/A:N
6.1Arista NetworksCVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:U/C:H/I:H/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-319Cleartext Transmission of Sensitive Information
CWE-255Credentials Management Errors

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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