SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityModified

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.

HIGH 7.5EPSS 1.00%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (1.00%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.

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.

CVSS 3.1
7.5 HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
EPSS
1.00% probability · 63th percentile
Public exploits
None in Exploit-DB
CISA KEV
Not listed
Weakness
CWE-400, CWE-1284
Affected
arista/eos
Source
psirt@arista.com
EPSS trend
0%3%5%26 October 2026: 1.00%26 October 202626 October 2026

EPSS 1.0% since 26 October 2026; no change recorded yet. Points are recorded when the score first appears and whenever it moves by a percentage point or more.

Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.