dbcve.org
EosOperating system · Arista

CVE-2021-28510

HIGH · 7.5 CVSS v3.1 Published 2023-01-26
Fix available
A fix is available. Upgrade to 4.23.10 / 4.24.8 or later.
See remediation →
84/100
Remediation priority · High
Public exploit Remotely reachable No privileges Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
For certain systems running EOS, a Precision Time Protocol (PTP) packet of a management/signaling message with an invalid Type-Length-Value (TLV) causes the PTP agent to restart. Repeated restarts of the service will make the service unavailable.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis
How this class of weakness works · CWE-400

A single request can consume unbounded CPU, memory, or connections, so a modest amount of malicious traffic exhausts the service. The result is denial of service for everyone else. Remediation is enforcing limits, quotas, and timeouts on what any one request can use.

General guidance for the uncontrolled resource consumption class — the official description and references above are authoritative for this specific CVE. Want a bespoke review and a reviewed fix? Ask our team →

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
EosOperating system
Affected:< 4.23.10>= 4.24.0, < 4.24.8>= 4.25.0, < 4.25.6>= 4.26.0, < 4.26.4>= 4.27.0, < 4.27.1

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Upgrade available Upgrade to 4.23.10 / 4.24.8 / 4.25.6 or later
Fixed in 4.23.104.24.84.25.6
Recommended fix High confidence

4.23.10, 4.24.8, 4.25.6, or 4.26.4 (depending on which major release train you are on)

  1. 1. Identify the current EOS version by running 'show version' on the device
  2. 2. Based on the current version, determine the target fixed release: if < 4.23.10, upgrade to 4.23.10; if >= 4.24.0 and < 4.24.8, upgrade to 4.24.8; if >= 4.25.0 and < 4.25.6, upgrade to 4.25.6; if >= 4.26.0 and < 4.26.4, upgrade to 4.26.4
  3. 3. Download the appropriate EOS software image from the Arista portal (requires valid support contract)
  4. 4. Verify the software image integrity using checksums provided by Arista
  5. 5. Schedule a maintenance window as upgrade will cause brief service disruption
  6. 6. Upload the new EOS image to the device using 'copy http://... flash:' or other transfer method
  7. 7. Configure the device to boot from the new image using 'boot system flash:<new-image-name>'
  8. 8. Reload the device using 'reload' command
Caveat Standard EOS upgrade may cause brief traffic disruption; ensure redundant paths exist and plan for failover during maintenance window

Generated from the published advisory — verify against the referenced sources before acting.

We can perform the upgrade in your staging environment and verify nothing breaks — typical engagement from $1,950. Get the upgrade done

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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2021-28510 in production — separate from our analysis above.

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
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