CVE-2021-1231

lowpriority · track · 19EPSS 0.003 · 17 %ileEURUUS

grimoire priorityP3 · Track

Exploitable?

—

no known exploitation

Likely / severe?

0.25% (17th) EPSS

CVSS 2.9 · low

Is it mine?

237 products

Check your exposure

Who says so?

4 sources

cnnvd · enisa_euvd · fstec_bdu · cisco_csaf

EPSS · scored 2026-10-27

A vulnerability in the Link Layer Discovery Protocol (LLDP) for Nexus 9000 Series Fabric Switches in Application Centric Infrastructure (ACI) mode could allow an unauthenticated, adjacent attacker to disable switching on a small form-factor pluggable (SFP) interface. This vulnerability is due to incomplete validation of the source of a received LLDP packet. An attacker could exploit this vulnerability by sending a crafted LLDP packet on an SFP interface to an affected device. A successful exploit could allow the attacker to disable switching on the SFP interface, which could disrupt network traffic.

remediations

Vendor fix, mitigation, or workaround guidance, as published by each source.

A vendor fix is available.

FixedCisco NX-OS System Software in ACI Mode 13.2(1l) when installed on Cisco Nexus 9000 Series Switchescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco NX-OS System Software in ACI Mode 13.2(1m) when installed on Cisco Nexus 9000 Series Switchescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco NX-OS System Software in ACI Mode 13.2(2l) when installed on Cisco Nexus 9000 Series Switchescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco NX-OS System Software in ACI Mode 13.2(2o) when installed on Cisco Nexus 9000 Series Switchescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco NX-OS System Software in ACI Mode 13.2(3i) when installed on Cisco Nexus 9000 Series Switchescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco NX-OS System Software in ACI Mode 13.2(3j) when installed on Cisco Nexus 9000 Series Switchescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco NX-OS System Software in ACI Mode 13.2(3n) when installed on Cisco Nexus 9000 Series Switchescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco NX-OS System Software in ACI Mode 13.2(3o) when installed on Cisco Nexus 9000 Series Switchescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco NX-OS System Software in ACI Mode 13.2(3r) when installed on Cisco Nexus 9000 Series Switchescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco NX-OS System Software in ACI Mode 13.2(3s) when installed on Cisco Nexus 9000 Series Switchescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco NX-OS System Software in ACI Mode 13.2(41d) when installed on Cisco Nexus 9000 Series Switchescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco NX-OS System Software in ACI Mode 13.2(4d) when installed on Cisco Nexus 9000 Series Switchescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco NX-OS System Software in ACI Mode 13.2(4e) when installed on Cisco Nexus 9000 Series Switchescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco NX-OS System Software in ACI Mode 13.2(5d) when installed on Cisco Nexus 9000 Series Switchescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco NX-OS System Software in ACI Mode 13.2(5e) when installed on Cisco Nexus 9000 Series Switchescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco NX-OS System Software in ACI Mode 13.2(5f) when installed on Cisco Nexus 9000 Series Switchescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco NX-OS System Software in ACI Mode 13.2(6i) when installed on Cisco Nexus 9000 Series Switchescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco NX-OS System Software in ACI Mode 13.2(7f) when installed on Cisco Nexus 9000 Series Switchescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco NX-OS System Software in ACI Mode 13.2(7k) when installed on Cisco Nexus 9000 Series Switchescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco NX-OS System Software in ACI Mode 13.2(8d) when installed on Cisco Nexus 9000 Series Switchescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco NX-OS System Software in ACI Mode 13.2(9b) when installed on Cisco Nexus 9000 Series Switchescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco NX-OS System Software in ACI Mode 13.2(9f) when installed on Cisco Nexus 9000 Series Switchescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco NX-OS System Software in ACI Mode 13.2(9h) when installed on Cisco Nexus 9000 Series Switchescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco NX-OS System Software in ACI Mode 14.0(1h) when installed on Cisco Nexus 9000 Series Switchescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco NX-OS System Software in ACI Mode 14.0(2c) when installed on Cisco Nexus 9000 Series Switchescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco NX-OS System Software in ACI Mode 14.0(3c) when installed on Cisco Nexus 9000 Series Switchescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco NX-OS System Software in ACI Mode 14.0(3d) when installed on Cisco Nexus 9000 Series Switchescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco NX-OS System Software in ACI Mode 14.1(1i) when installed on Cisco Nexus 9000 Series Switchescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco NX-OS System Software in ACI Mode 14.1(1j) when installed on Cisco Nexus 9000 Series Switchescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco NX-OS System Software in ACI Mode 14.1(1k) when installed on Cisco Nexus 9000 Series Switchescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco NX-OS System Software in ACI Mode 14.1(1l) when installed on Cisco Nexus 9000 Series Switchescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco NX-OS System Software in ACI Mode 14.1(2g) when installed on Cisco Nexus 9000 Series Switchescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco NX-OS System Software in ACI Mode 14.1(2m) when installed on Cisco Nexus 9000 Series Switchescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco NX-OS System Software in ACI Mode 14.1(2o) when installed on Cisco Nexus 9000 Series Switchescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco NX-OS System Software in ACI Mode 14.1(2s) when installed on Cisco Nexus 9000 Series Switchescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco NX-OS System Software in ACI Mode 14.1(2u) when installed on Cisco Nexus 9000 Series Switchescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco NX-OS System Software in ACI Mode 14.1(2w) when installed on Cisco Nexus 9000 Series Switchescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco NX-OS System Software in ACI Mode 14.1(2x) when installed on Cisco Nexus 9000 Series Switchescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco NX-OS System Software in ACI Mode 14.2(1i) when installed on Cisco Nexus 9000 Series Switchescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco NX-OS System Software in ACI Mode 14.2(1j) when installed on Cisco Nexus 9000 Series Switchescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco NX-OS System Software in ACI Mode 14.2(1l) when installed on Cisco Nexus 9000 Series Switchescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco NX-OS System Software in ACI Mode 14.2(2e) when installed on Cisco Nexus 9000 Series Switchescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco NX-OS System Software in ACI Mode 14.2(2f) when installed on Cisco Nexus 9000 Series Switchescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco NX-OS System Software in ACI Mode 14.2(2g) when installed on Cisco Nexus 9000 Series Switchescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco NX-OS System Software in ACI Mode 14.2(3j) when installed on Cisco Nexus 9000 Series Switchescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco NX-OS System Software in ACI Mode 14.2(3l) when installed on Cisco Nexus 9000 Series Switchescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco NX-OS System Software in ACI Mode 14.2(3n) when installed on Cisco Nexus 9000 Series Switchescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco NX-OS System Software in ACI Mode 14.2(3q) when installed on Cisco Nexus 9000 Series Switchescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco NX-OS System Software in ACI Mode 14.2(4i) when installed on Cisco Nexus 9000 Series Switchescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco NX-OS System Software in ACI Mode 14.2(4k) when installed on Cisco Nexus 9000 Series Switchescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco NX-OS System Software in ACI Mode 14.2(4o) when installed on Cisco Nexus 9000 Series Switchescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco NX-OS System Software in ACI Mode 14.2(4p) when installed on Cisco Nexus 9000 Series Switchescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco NX-OS System Software in ACI Mode 14.2(5k) when installed on Cisco Nexus 9000 Series Switchescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco NX-OS System Software in ACI Mode 15.0(1k) when installed on Cisco Nexus 9000 Series Switchescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco NX-OS System Software in ACI Mode 15.0(1l) when installed on Cisco Nexus 9000 Series Switchescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco NX-OS System Software in ACI Mode 15.0(2e) when installed on Cisco Nexus 9000 Series Switchescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
FixedCisco NX-OS System Software in ACI Mode 15.0(2h) when installed on Cisco Nexus 9000 Series Switchescisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com

cvss

Technical severity, 0–10. One row per scoring source.

4.7

010

base score 0–10 · higher = more severe · hover a vector to decode⚠ sources disagree · low–medium · 2.9–4.7

v2.02.9lowAV:A/AC:M/Au:N/C:N/I:N/A:Pprimary · NVD / NIST USexploitability 5.5 · impact 2.9

v3.14.7mediumCVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:Lprimary · NVD / NIST USexploitability 2.8 · impact 1.4

v3.14.7mediumAV:A/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:Lsecondary · FSTEC (BDU) RU

v3.14.7mediumCVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:Lsecondary · ENISA EU

v3.14.7mediumCVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:Lsecondary · psirt@cisco.com USexploitability 2.8 · impact 1.4

v3.14.3mediumCVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:L/E:Usecondary · CVSS-BT (t0sche)

v3.14.7mediumCVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:Lsecondary · Cisco PSIRT US

ssvc

A stakeholder decision — act, attend, or track — from exploitation and impact.

Trackcoordinatorcisa_ssvcUS

weaknesses

The CWE weakness classes this flaw belongs to.

CWE-346USprimaryCWE-284USCWE-284US

affected products (237)

Products and version ranges known to be affected.

showing 20 of 237

advisories (1)

Vendor and ecosystem advisories describing this.

cisco-sa-apic-lldap-dos-WerV9CFjCisco Nexus 9000 Series Fabric Switches ACI Mode Link Layer Discovery Protocol Port Denial of Service Vulnerability2021-02-24csaf · cisco_csafUS
A vulnerability in the Link Layer Discovery Protocol (LLDP) for Nexus 9000 Series Fabric Switches in Application Centric Infrastructure (ACI) mode could allow an unauthenticated, adjacent attacker to disable switching on a small form-factor pluggable (SFP) interface. This vulnerability is due to incomplete validation of the source of a received LLDP packet. An attacker could exploit this vulnerability by sending a crafted LLDP packet on an SFP interface to an affected device. A successful exploit could allow the attacker to disable switching on the SFP interface, which could disrupt network traffic. Cisco has released software updates that address this vulnerability. There are no workarounds that address this vulnerability.

also known as (4)

Other names and identifiers for this entity.

sources

Which sources assert this record, and when.

cnnvd enisa_euvd fstec_bdu cisco_csaf NVD CVE.org MITRE

published 2021-02-24modified 2026-06-17

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references (6)

External citations — patches, advisories, analysis.

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