CVE-2020-11622Network attack vector

Unauthenticated traffic-forwarding denial via malformed TCP packet

Published Jun 10, 2020 · Updated Aug 4, 2024

Denial of service in Arista CloudEOS VM/vEOS Router releases allows remote attackers to interrupt data-plane traffic forwarding via a malformed TCP packet. The CloudEOS/vEOS forwarding code mishandles packets when a tunnel interface has a configured TCP MSS ceiling, causing forwarding failure and potentially hanging the BESS port-status command. Exploitation requires a reachable data-plane path and the tcp mss ceiling configuration; recovery can require restarting the SFE agent, with forwarding unavailable for up to three minutes.

CVSS severity7.5
High
EPSS probability1.28%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Denial of service in Arista CloudEOS VM/vEOS Router releases allows remote attackers to interrupt data-plane traffic forwarding via a malformed TCP packet. The CloudEOS/vEOS forwarding code mishandles packets when a tunnel interface has a configured TCP MSS ceiling, causing forwarding failure and potentially hanging the BESS port-status command. Exploitation requires a reachable data-plane path and the tcp mss ceiling configuration; recovery can require restarting the SFE agent, with forwarding unavailable for up to three minutes.

The record

CVE
CVE-2020-11622
Published
Jun 10, 2020
Updated
Aug 4, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
T1499
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jun 10, 2020CVE publishedPublication date reported by the CVE source.
  2. Aug 4, 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?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

7.5Arista NetworksCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
4.3NVDAV:N/AC:M/Au:N/C:N/I:N/A:P

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
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

T1499Endpoint Denial of Service

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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