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01 Record

CVE-2021-28510

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.

MediumPUBLISHEDCNA: Arista
CNA base score5.3 CVSS v3.xCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

02 Description

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.

03 Exploitation and scoring

Exploitation
Public exploit code exists. CISA's assessment records a public proof of concept. That is not a report of exploitation in the wild.
SSVC decision
  • ExploitationpocPublic proof-of-concept exploit code exists. Not a report of exploitation in the wild.
  • AutomatableyesAn attacker can reliably automate reconnaissance through exploitation, so this scales.
  • Technical ImpactpartialSuccessful exploitation gives limited control of the vulnerable component.
CISA publishes the decision points, not a final SSVC decision. The decision also depends on mission and well-being impact, which is a property of your deployment rather than of the vulnerability.
EPSS probability
1.00% probability of exploitation activity in the next 30 days.
EPSS percentile
Equal to or higher than the score of 62.5% of scored records. A rank, not a probability.
NVD base score
7.5 (CVSS v3.x), scored by the NVD independently of the CNA.
NVD CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
NVD analysis status
Modified. NVD last modified this record on 2026-06-17.
Red Hat severity
No Red Hat rating. Red Hat rates the CVEs that affect its products.

Exploit-prediction scores from FIRST. Independent scoring and analysis status from the NVD. Vendor severity from Red Hat. Exploitation assessment and catalog membership from CISA.

04 Metadata

Published
2023-01-24 00:00Z3 YR AGO
Last updated
2025-04-01 18:44Z1 YR AGO
Reserved
2021-03-16
Assigning CNA
Arista
Record state
PUBLISHED
Severity
Medium (CVSS 5.3)
CNA CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
Weaknesses
  • CWE-400Uncontrolled Resource ConsumptionClass
  • CWE-1284Improper Validation of Specified Quantity in InputBase
Data version
5.1
Document digest
f2b5db0440eee4fbbbb4f3a7329e7dbc46259af7e8b7949d85aa09a8ce202d35

05 Affected products

VendorProductVersionsPlatforms
Arista NetworksEOS4.22, 4.27.1 to 4.27.0, 4.26.4 to 4.26.0, 4.25.6 to 4.25.0, 4.24.8 to 4.24.0, 4.23.10 to 4.23.0—

06 References

07 Remediation

The recommended resolution is to upgrade to a remediated software version at your earliest convenience. Artista recommends customers move to the latest version of each release that contains all the fixes listed below. CVE-2021-28510 has been fixed in the following releases: 4.27.2 and later releases in the 4.27.x train 4.26.5 and later releases in the 4.26.x train 4.25.7 and later releases in the 4.25.x train 4.24.9 and later releases in the 4.24.x train 4.23.11 and later releases in the 4.23.x train

Hotfix The following hotfix can be applied to remediate CVE-2021-28510 Note: Installing/uninstalling the SWIX will cause the PTP agent to restart. Version: 1.0 URL:SecurityAdvisory76_CVE-2021-28510_Hotfix.swix SWIX hash: (SHA-512)2b78b8274b7c73083775b0327e13819c655db07e22b80038bb3843002c679a798b53a4638c549a86183e01a835377bf262d27e60020a39516a5d215e2fadb437