Security readout for executives and security teams
Plain-English summary
This vulnerability can expose MACsec secrets through Arista telemetry streaming into CVP. If the affected setup is present, another authorized CVP user could see sensitive MACsec data and potentially decrypt or alter protected traffic. It is not a broad unauthenticated internet attack, but it matters where MACsec protects critical links.
Executive priority
Treat as a targeted confidentiality and integrity risk for environments relying on MACsec. Prioritize affected Arista/CVP deployments with broad admin access or sensitive encrypted links, but do not treat it as mass-exploited based on the provided evidence.
Technical view
Arista reports that EOS TerminAttr and OpenConfig transport protocols can stream MACsec sensitive data in clear text to CVP under certain conditions. The CVSS vector requires network access, high privileges, and user interaction, with high confidentiality and integrity impact and no availability impact.
Likely exposure
Exposure is likely limited to Arista EOS 4.23 through 4.27 and TerminAttr v1.10, v1.16, or v1.19 deployments using CVP telemetry with MACsec-related data present.
Exploitation context
The bundle does not show CISA KEV listing or other evidence of active exploitation. The attacker model is an authorized user path, not anonymous access. Business risk depends on who can access CVP telemetry and whether MACsec protects sensitive network traffic.
Researcher notes
The key unknown is the exact vendor-fixed release path, because the supplied bundle names the advisory but does not include remediation text. Validate affected versions, telemetry configuration, CVP authorization boundaries, and whether MACsec secrets are exposed in streamed state.
Mitigation direction
- Review Arista Security Advisory 0077 for vendor-approved fixed versions and upgrade guidance.
- Restrict CVP access to users with a clear operational need.
- Review roles and permissions for users who can view streamed telemetry.
- Limit exposure of MACsec sensitive telemetry until vendor remediation is applied.
Validation and detection
- Inventory Arista EOS versions 4.23, 4.24, 4.25, 4.26, and 4.27.
- Inventory TerminAttr versions v1.10, v1.16, and v1.19.
- Confirm whether TerminAttr or OpenConfig telemetry streams into CVP.
- Confirm whether MACsec is configured on devices using affected telemetry paths.
- Review CVP user access for roles able to view streamed device state.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
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CWE-255: Exact CWE lookup
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Open ATT&CK lookupCVE-2021-28509 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- Medium
- CVSS
- 6.1 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:U/C:H/I:H/A:N
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
CVSS vector scores
1 official scoreWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:U/C:H/I:H/A:N0.95.2Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
6.1MediumVector: CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:U/C:H/I:H/A:N
Source materials
- CVE List V5 sourceCVE List V5
- https://www.arista.com/en/support/advisories-notices/security-advisories/15484-security-advisory-0077CVE reference · x_refsource_MISC
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.
Credentials Management Errors
Credentials Management Errors represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.