{"schema_version":"public-product-v1.1","generated_at":"2026-07-21T11:03:02Z","exposure_verdict":"not_assessed","verdict_reason":"Public evidence does not evaluate exact release, platform, enabled features, configuration, compensating controls, or live exposure.","advisory":{"id":"cisco-sa-apic-lldap-dos-WerV9CFj","slug":"cisco-sa-apic-lldap-dos-werv9cfj","vendor":"Cisco","title":"Cisco Nexus 9000 Series Fabric Switches ACI Mode Link Layer Discovery Protocol Port Denial of Service Vulnerability","summary":"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. This advisory is available at the following link:https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-apic-lldap-dos-WerV9CFj","severity":"Medium","published_at":"2021-02-24T16:00:00Z","updated_at":"2021-02-24T16:00:00Z","source_url":"https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-apic-lldap-dos-WerV9CFj","csaf_url":"https://sec.cloudapps.cisco.com/security/center/contentjson/CiscoSecurityAdvisory/cisco-sa-apic-lldap-dos-WerV9CFj/csaf/cisco-sa-apic-lldap-dos-WerV9CFj.json","exposure_verdict":"not_assessed","verdict_reason":"Public evidence does not evaluate exact release, platform, enabled features, configuration, compensating controls, or live exposure."},"freshness":{"last_source_refreshed_at":"2026-07-21T05:16:34Z","latest_source_refresh_at":"2026-07-21T05:16:34Z","oldest_source_refresh_at":"2026-07-21T03:00:03Z","all_sources_fresh":true,"sources":[{"source":"cisco_advisories","label":"Cisco advisories","last_success_at":"2026-07-21T03:00:03Z","stale":false},{"source":"cisco_csaf","label":"Cisco CSAF","last_success_at":"2026-07-21T05:14:24Z","stale":false},{"source":"nvd_cves","label":"NVD CVEs","last_success_at":"2026-07-21T05:16:30Z","stale":false},{"source":"cisa_kev","label":"CISA KEV","last_success_at":"2026-07-21T05:16:31Z","stale":false},{"source":"first_epss","label":"EPSS","last_success_at":"2026-07-21T05:16:34Z","stale":false}]},"summary":{"cve_count":1,"visible_product_count":1,"public_evidence_count":1,"kev_count":0,"highest_epss":0.00244},"cves":[{"id":"CVE-2021-1231","kev":false,"epss":{"score":0.00244,"percentile":0.15633,"score_date":"2026-07-20","updated_at":"2026-07-21T05:16:34Z"}}],"public_evidence":[{"product":{"name":"Cisco Nexus 9000 Series Switches","slug":"cisco-nexus-9000-series-switches","vendor":"Cisco"},"cve":{"id":"CVE-2021-1231"},"evidence_type":"structured_affected","evidence_label":{"scope":"CSAF product evidence","label":"product_status known affected"},"evidence_source":"Cisco CSAF","source":"Cisco CSAF","source_document_fetched_at":"2026-07-20T04:21:54Z","csaf_status":"known_affected","csaf_product_status":"known_affected","csaf_product_status_path":"vulnerabilities[].product_status.known_affected","raw_product_name":"Cisco NX-OS System Software in ACI Mode 13.2(1l) when installed on Cisco Nexus 9000 Series Switches; Cisco NX-OS System Software in ACI Mode 13.2(1m) when installed on Cisco Nexus 9000 Series Switches; Cisco NX-OS System Software in ACI Mode 13.2(2l) when installed on Cisco Nexus 9000 Series Switches; Cisco NX-OS System Software in ACI Mode 13.2(2o) when installed on Cisco Nexus 9000 Series Switches; Cisco NX-OS System Software in ACI Mode 13.2(3i) when installed on Cisco Nexus 9000 Series Switches; Cisco NX-OS System Software in ACI Mode 13.2(3j) when installed on Cisco Nexus 9000 Series Switches; Cisco NX-OS System Software in ACI Mode 13.2(3n) when installed on Cisco Nexus 9000 Series Switches; Cisco NX-OS System Software in ACI Mode 13.2(3o) when installed on Cisco Nexus 9000 Series Switches; Cisco NX-OS System Software in ACI Mode 13.2(3r) when installed on Cisco Nexus 9000 Series Switches; Cisco NX-OS System Software in ACI Mode 13.2(3s) when installed on Cisco Nexus 9000 Series Switches; Cisco NX-OS System Software in ACI Mode 13.2(41d) when installed on Cisco Nexus 9000 Series Switches; Cisco NX-OS System Software in ACI Mode 13.2(4d) when installed on Cisco Nexus 9000 Series Switches; Cisco NX-OS System Software in ACI Mode 13.2(4e) when installed on Cisco Nexus 9000 Series Switches; Cisco NX-OS System Software in ACI Mode 13.2(5d) when installed on Cisco Nexus 9000 Series Switches; Cisco NX-OS System Software in ACI Mode 13.2(5e) when installed on Cisco Nexus 9000 Series Switches; Cisco NX-OS System Software in ACI Mode 13.2(5f) when installed on Cisco Nexus 9000 Series Switches; Cisco NX-OS System Software in ACI Mode 13.2(6i) when installed on Cisco Nexus 9000 Series Switches; Cisco NX-OS System Software in ACI Mode 13.2(7f) when installed on Cisco Nexus 9000 Series Switches; Cisco NX-OS System Software in ACI Mode 13.2(7k) when installed on Cisco Nexus 9000 Series Switches; Cisco NX-OS System Software in ACI Mode 13.2(8d) when installed on Cisco Nexus 9000 Series Switches; Cisco NX-OS System Software in ACI Mode 13.2(9b) when installed on Cisco Nexus 9000 Series Switches; Cisco NX-OS System Software in ACI Mode 13.2(9f) when installed on Cisco Nexus 9000 Series Switches; Cisco NX-OS System Software in ACI Mode 13.2(9h) when installed on Cisco Nexus 9000 Series Switches; Cisco NX-OS System Software in ACI Mode 14.0(1h) when installed on Cisco Nexus 9000 Series Switches; Cisco NX-OS System Software in ACI Mode 14.0(2c) when installed on Cisco Nexus 9000 Series Switches; Cisco NX-OS System Software in ACI Mode 14.0(3c) when installed on Cisco Nexus 9000 Series Switches; Cisco NX-OS System Software in ACI Mode 14.0(3d) when installed on Cisco Nexus 9000 Series Switches; Cisco NX-OS System Software in ACI Mode 14.1(1i) when installed on Cisco Nexus 9000 Series Switches; Cisco NX-OS System Software in ACI Mode 14.1(1j) when installed on Cisco Nexus 9000 Series Switches; Cisco NX-OS System Software in ACI Mode 14.1(1k) when installed on Cisco Nexus 9000 Series Switches; Cisco NX-OS System Software in ACI Mode 14.1(1l) when installed on Cisco Nexus 9000 Series Switches; Cisco NX-OS System Software in ACI Mode 14.1(2g) when installed on Cisco Nexus 9000 Series Switches; Cisco NX-OS System Software in ACI Mode 14.1(2m) when installed on Cisco Nexus 9000 Series Switches; Cisco NX-OS System Software in ACI Mode 14.1(2o) when installed on Cisco Nexus 9000 Series Switches; Cisco NX-OS System Software in ACI Mode 14.1(2s) when installed on Cisco Nexus 9000 Series Switches; Cisco NX-OS System Software in ACI Mode 14.1(2u) when installed on Cisco Nexus 9000 Series Switches; Cisco NX-OS System Software in ACI Mode 14.1(2w) when installed on Cisco Nexus 9000 Series Switches; Cisco NX-OS System Software in ACI Mode 14.1(2x) when installed on Cisco Nexus 9000 Series Switches; Cisco NX-OS System Software in ACI Mode 14.2(1i) when installed on Cisco Nexus 9000 Series Switches; Cisco NX-OS System Software in ACI Mode 14.2(1j) when installed on Cisco Nexus 9000 Series Switches; Cisco NX-OS System Software in ACI Mode 14.2(1l) when installed on Cisco Nexus 9000 Series Switches; Cisco NX-OS System Software in ACI Mode 14.2(2e) when installed on Cisco Nexus 9000 Series Switches; Cisco NX-OS System Software in ACI Mode 14.2(2f) when installed on Cisco Nexus 9000 Series Switches; Cisco NX-OS System Software in ACI Mode 14.2(2g) when installed on Cisco Nexus 9000 Series Switches; Cisco NX-OS System Software in ACI Mode 14.2(3j) when installed on Cisco Nexus 9000 Series Switches; Cisco NX-OS System Software in ACI Mode 14.2(3l) when installed on Cisco Nexus 9000 Series Switches; Cisco NX-OS System Software in ACI Mode 14.2(3n) when installed on Cisco Nexus 9000 Series Switches; Cisco NX-OS System Software in ACI Mode 14.2(3q) when installed on Cisco Nexus 9000 Series Switches; Cisco NX-OS System Software in ACI Mode 14.2(4i) when installed on Cisco Nexus 9000 Series Switches; Cisco NX-OS System Software in ACI Mode 14.2(4k) when installed on Cisco Nexus 9000 Series Switches; Cisco NX-OS System Software in ACI Mode 14.2(4o) when installed on Cisco Nexus 9000 Series Switches; Cisco NX-OS System Software in ACI Mode 14.2(4p) when installed on Cisco Nexus 9000 Series Switches; Cisco NX-OS System Software in ACI Mode 14.2(5k) when installed on Cisco Nexus 9000 Series Switches; Cisco NX-OS System Software in ACI Mode 15.0(1k) when installed on Cisco Nexus 9000 Series Switches; Cisco NX-OS System Software in ACI Mode 15.0(1l) when installed on Cisco Nexus 9000 Series Switches; Cisco NX-OS System Software in ACI Mode 15.0(2e) when installed on Cisco Nexus 9000 Series Switches; Cisco NX-OS System Software in ACI Mode 15.0(2h) when installed on Cisco Nexus 9000 Series Switches","exposure_verdict":"not_assessed","verdict_reason":"Public evidence does not evaluate exact release, platform, enabled features, configuration, compensating controls, or live exposure.","exposure_verdict_reason":"Public evidence does not evaluate exact release, platform, enabled features, configuration, compensating controls, or live exposure.","kev":false,"epss":{"score":0.00244,"score_date":"2026-07-20","updated_at":"2026-07-21T05:16:34Z"},"published_at":"2021-02-24T16:00:00Z","updated_at":"2021-02-24T16:00:00Z","advisory_updated_at":"2021-02-24T16:00:00Z","source_url":"https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-apic-lldap-dos-WerV9CFj","remediation":{"url":"https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-apic-lldap-dos-WerV9CFj"},"row_display_order":1}]}